Why is a Windows user getting permission denied attempting to connect to vsftpd server?

I have a Ubuntu 18 LTS server running vsftpd. Several users are able to use the ftp service without any issues but one user consistently gets an error attempting to connect to the server. The user with the issue is connecting from a Windows computer and gets a pop up that says

An error occurred opening that folder on the FTP Server.
Make sure you have permission to access that folder.
Details:
200 Switching to ASCII mode.
227 Entering Passive Mode (172,31,85,112,156,101).

I am using a MacBook Pro and can connect to the same account he is trying to use without any problems. Once I connect I can upload files, download files, and delete files with two different ftp apps (FileZilla and Cyberduck).

Here are the non-commented lines from the vsftpd.conf file.

listen=NO
listen_ipv6=YES
anonymous_enable=NO
local_enable=YES
write_enable=YES
local_umask=013
dirmessage_enable=YES
use_localtime=YES
xferlog_enable=YES
connect_from_port_20=YES
xferlog_std_format=NO
log_ftp_protocol=YES
async_abor_enable=YES
ascii_upload_enable=YES
ascii_download_enable=YES
chroot_local_user=YES
chroot_list_enable=NO
allow_writeable_chroot=YES
ls_recurse_enable=YES
secure_chroot_dir=/var/run/vsftpd/empty
pam_service_name=vsftpd
max_clients=20
max_per_ip=4
pasv_enable=YES
pasv_max_port=40100
pasv_min_port=40000

I turned up the logging on the server and here's what I see when he attempts to connect. I've changed the IP addresses to "XXX.XXX.XXX.XXX" and username to "ftpuser" here but the rest is an exact copy of what is in the log.

Tue Apr 28 15:25:45 2020 [pid 14174] FTP command: Client "::ffff:XXX.XXX.XXX.XXX", "USER ftpuser"
Tue Apr 28 15:25:45 2020 [pid 14174] [ftpuser] FTP response: Client "::ffff:XXX.XXX.XXX.XXX", "331 Please specify the password."
Tue Apr 28 15:25:45 2020 [pid 14174] [ftpuser] FTP command: Client "::ffff:XXX.XXX.XXX.XXX", "PASS <password>"
Tue Apr 28 15:25:45 2020 [pid 14173] [ftpuser] OK LOGIN: Client "::ffff:XXX.XXX.XXX.XXX"
Tue Apr 28 15:25:46 2020 [pid 14175] [ftpuser] FTP response: Client "::ffff:XXX.XXX.XXX.XXX", "230 Login successful."
Tue Apr 28 15:25:46 2020 [pid 14175] [ftpuser] FTP command: Client "::ffff:XXX.XXX.XXX.XXX", "OPTS utf8 on"
Tue Apr 28 15:25:46 2020 [pid 14175] [ftpuser] FTP response: Client "::ffff:XXX.XXX.XXX.XXX", "200 Always in UTF8 mode."
Tue Apr 28 15:25:46 2020 [pid 14175] [ftpuser] FTP command: Client "::ffff:XXX.XXX.XXX.XXX", "SYST"
Tue Apr 28 15:25:46 2020 [pid 14175] [ftpuser] FTP response: Client "::ffff:XXX.XXX.XXX.XXX", "215 UNIX Type: L8"
Tue Apr 28 15:25:46 2020 [pid 14175] [ftpuser] FTP command: Client "::ffff:XXX.XXX.XXX.XXX", "SITE help"
Tue Apr 28 15:25:46 2020 [pid 14175] [ftpuser] FTP response: Client "::ffff:XXX.XXX.XXX.XXX", "214 CHMOD UMASK HELP"
Tue Apr 28 15:25:46 2020 [pid 14175] [ftpuser] FTP command: Client "::ffff:XXX.XXX.XXX.XXX", "PWD"
Tue Apr 28 15:25:46 2020 [pid 14175] [ftpuser] FTP response: Client "::ffff:XXX.XXX.XXX.XXX", "257 "/" is the current directory"
Tue Apr 28 15:25:46 2020 [pid 14177] FTP command: Client "::ffff:XXX.XXX.XXX.XXX", "USER ftpuser"
Tue Apr 28 15:25:46 2020 [pid 14177] [ftpuser] FTP response: Client "::ffff:XXX.XXX.XXX.XXX", "331 Please specify the password."
Tue Apr 28 15:25:46 2020 [pid 14177] [ftpuser] FTP command: Client "::ffff:XXX.XXX.XXX.XXX", "PASS <password>"
Tue Apr 28 15:25:46 2020 [pid 14176] [ftpuser] OK LOGIN: Client "::ffff:XXX.XXX.XXX.XXX"
Tue Apr 28 15:25:46 2020 [pid 14178] [ftpuser] FTP response: Client "::ffff:XXX.XXX.XXX.XXX", "230 Login successful."
Tue Apr 28 15:25:46 2020 [pid 14178] [ftpuser] FTP command: Client "::ffff:XXX.XXX.XXX.XXX", "OPTS utf8 on"
Tue Apr 28 15:25:46 2020 [pid 14178] [ftpuser] FTP response: Client "::ffff:XXX.XXX.XXX.XXX", "200 Always in UTF8 mode."
Tue Apr 28 15:25:46 2020 [pid 14178] [ftpuser] FTP command: Client "::ffff:XXX.XXX.XXX.XXX", "SYST"
Tue Apr 28 15:25:46 2020 [pid 14178] [ftpuser] FTP response: Client "::ffff:XXX.XXX.XXX.XXX", "215 UNIX Type: L8"
Tue Apr 28 15:25:46 2020 [pid 14178] [ftpuser] FTP command: Client "::ffff:XXX.XXX.XXX.XXX", "SITE help"
Tue Apr 28 15:25:46 2020 [pid 14178] [ftpuser] FTP response: Client "::ffff:XXX.XXX.XXX.XXX", "214 CHMOD UMASK HELP"
Tue Apr 28 15:25:46 2020 [pid 14178] [ftpuser] FTP command: Client "::ffff:XXX.XXX.XXX.XXX", "PWD"
Tue Apr 28 15:25:46 2020 [pid 14178] [ftpuser] FTP response: Client "::ffff:XXX.XXX.XXX.XXX", "257 "/" is the current directory"
Tue Apr 28 15:25:46 2020 [pid 14178] [ftpuser] FTP command: Client "::ffff:XXX.XXX.XXX.XXX", "TYPE A"
Tue Apr 28 15:25:46 2020 [pid 14178] [ftpuser] FTP response: Client "::ffff:XXX.XXX.XXX.XXX", "200 Switching to ASCII mode."
Tue Apr 28 15:25:46 2020 [pid 14178] [ftpuser] FTP command: Client "::ffff:XXX.XXX.XXX.XXX", "PASV"
Tue Apr 28 15:25:46 2020 [pid 14178] [ftpuser] FTP response: Client "::ffff:XXX.XXX.XXX.XXX", "227 Entering Passive Mode (172,31,85,112,156,84)."
Tue Apr 28 15:25:46 2020 [pid 14180] FTP command: Client "::ffff:XXX.XXX.XXX.XXX", "USER ftpuser"
Tue Apr 28 15:25:46 2020 [pid 14180] [ftpuser] FTP response: Client "::ffff:XXX.XXX.XXX.XXX", "331 Please specify the password."
Tue Apr 28 15:25:46 2020 [pid 14180] [ftpuser] FTP command: Client "::ffff:XXX.XXX.XXX.XXX", "PASS <password>"
Tue Apr 28 15:25:46 2020 [pid 14179] [ftpuser] OK LOGIN: Client "::ffff:XXX.XXX.XXX.XXX"
Tue Apr 28 15:25:46 2020 [pid 14181] [ftpuser] FTP response: Client "::ffff:XXX.XXX.XXX.XXX", "230 Login successful."
Tue Apr 28 15:25:46 2020 [pid 14181] [ftpuser] FTP command: Client "::ffff:XXX.XXX.XXX.XXX", "OPTS utf8 on"
Tue Apr 28 15:25:46 2020 [pid 14181] [ftpuser] FTP response: Client "::ffff:XXX.XXX.XXX.XXX", "200 Always in UTF8 mode."
Tue Apr 28 15:25:46 2020 [pid 14181] [ftpuser] FTP command: Client "::ffff:XXX.XXX.XXX.XXX", "PWD"
Tue Apr 28 15:25:46 2020 [pid 14181] [ftpuser] FTP response: Client "::ffff:XXX.XXX.XXX.XXX", "257 "/" is the current directory"
Tue Apr 28 15:25:46 2020 [pid 14181] [ftpuser] FTP command: Client "::ffff:XXX.XXX.XXX.XXX", "TYPE A"
Tue Apr 28 15:25:46 2020 [pid 14181] [ftpuser] FTP response: Client "::ffff:XXX.XXX.XXX.XXX", "200 Switching to ASCII mode."
Tue Apr 28 15:25:46 2020 [pid 14181] [ftpuser] FTP command: Client "::ffff:XXX.XXX.XXX.XXX", "PASV"
Tue Apr 28 15:25:46 2020 [pid 14181] [ftpuser] FTP response: Client "::ffff:XXX.XXX.XXX.XXX", "227 Entering Passive Mode (172,31,85,112,156,66)."

I've already tried a number of things, like turning on asnyc_abor_enable, enabling ASCII downloads and uploads, and setting ls_recurse_enable to YES. Those haven't worked and I can't reproduce the issue with my environment so I'm running out of ideas.

Any thoughts on what could cause this problem or other ways to troubleshoot it?

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