SSL VPN failed after system update in February

I have the Sophos UTM configured with a SSL VPN login that I've been using regularly for several years, logging in from 2 different clients.  The first is the Sophos UTM client itself on Windows 10 (current version, downloaded and reinstalled yesterday to be sure), the second is a gli.net mobile router with an OpenVPN client.

Sometime in February, I remember updating my UTM with two version updates ... it was the current version 9.714-4 and whatever was the update before that.  I didn't realize it till next time I tried to log in remotely, but one of these two updates must have broken the SSL VPN system.  Now when I try to log in the connection fails.

Just to be safe, I deleted and recreated my SSL certificate/config file before doing the following test.

Here's the log from the client (IP address obfuscated):

2023-03-21 17:34:48 WARNING: Compression for receiving enabled. Compression has been used in the past to break encryption. Sent packets are not compressed unless "allow-compression yes" is also set.
2023-03-21 17:34:48 DEPRECATED OPTION: --cipher set to 'AES-256-CBC' but missing in --data-ciphers (AES-256-GCM:AES-128-GCM). Future OpenVPN version will ignore --cipher for cipher negotiations. Add 'AES-256-CBC' to --data-ciphers or change --cipher 'AES-256-CBC' to --data-ciphers-fallback 'AES-256-CBC' to silence this warning.
2023-03-21 17:34:48 OpenVPN 2.5.6 Windows-MSVC [SSL (OpenSSL)] [LZO] [LZ4] [PKCS11] [AEAD] built on Apr 22 2022
2023-03-21 17:34:48 Windows version 10.0 (Windows 10 or greater) 64bit
2023-03-21 17:34:48 library versions: OpenSSL 1.1.1n 15 Mar 2022, LZO 2.10
2023-03-21 17:34:48 MANAGEMENT: TCP Socket listening on [AF_INET]127.0.0.1:25340
2023-03-21 17:34:48 Need hold release from management interface, waiting...
2023-03-21 17:34:48 MANAGEMENT: Client connected from [AF_INET]127.0.0.1:25340
2023-03-21 17:34:48 MANAGEMENT: CMD 'state on'
2023-03-21 17:34:48 MANAGEMENT: CMD 'log all on'
2023-03-21 17:34:48 MANAGEMENT: CMD 'echo all on'
2023-03-21 17:34:48 MANAGEMENT: CMD 'bytecount 5'
2023-03-21 17:34:48 MANAGEMENT: CMD 'hold off'
2023-03-21 17:34:48 MANAGEMENT: CMD 'hold release'
2023-03-21 17:34:48 MANAGEMENT: CMD 'username "Auth" xxx'  Note I obscured username
2023-03-21 17:34:48 MANAGEMENT: CMD 'password [...]'
2023-03-21 17:34:48 MANAGEMENT: >STATE:1679434488,RESOLVE,,,,,,
2023-03-21 17:34:48 TCP/UDP: Preserving recently used remote address: [AF_INET]x.x.x.x:443   Note obscured IP address here and below
2023-03-21 17:34:48 Socket Buffers: R=[65536->65536] S=[64512->64512]
2023-03-21 17:34:48 Attempting to establish TCP connection with [AF_INET]x.x.x.x:443 [nonblock]
2023-03-21 17:34:48 MANAGEMENT: >STATE:1679434488,TCP_CONNECT,,,,,,
2023-03-21 17:35:08 TCP: connect to [AF_INET]x.x.x.x:443 failed: Unknown error
2023-03-21 17:35:08 SIGUSR1[connection failed(soft),init_instance] received, process restarting
2023-03-21 17:35:08 MANAGEMENT: >STATE:1679434508,RECONNECTING,init_instance,,,,,
2023-03-21 17:35:08 Restart pause, 5 second(s)
2023-03-21 17:35:13 MANAGEMENT: Client disconnected
2023-03-21 17:35:13 All connections have been connect-retry-max (1) times unsuccessful, exiting
2023-03-21 17:35:13 Exiting due to fatal error

Meanwhile, here's the log for the same episode from the SSL log on the UTM itself:

2023:03:21-17:35:46 djwall openvpn[12983]: TCP connection established with [AF_INET]x.x.x.x:36773 (via [AF_INET]x.x.x.x:443)
2023:03:21-17:35:47 djwall openvpn[12983]: x.x.x.x:36773 Non-OpenVPN client protocol detected
2023:03:21-17:35:47 djwall openvpn[12983]: x.x.x.x:36773 SIGTERM[soft,port-share-redirect] received, client-instance exiting

I reemphasize -- all was working flawlessly on the same machines up until those updates.

I'd be really grateful for help in figuring out what's going wrong here.