authentication: operation timed out

[realSConway]

Using docker compose to deploy container, when trying to log in after entering username, password and custom url (same as ETESYNC_URL), see Deriving encryption keys, please wait… then error sending request for url (https://MY.CUSTOM.dedyn.io/api/v1/authentication/login_challenge/): operation timed out

container log:

514a5fa4f318 [2025-07-03 18:45:00 +0000] [1/Thread-1 (process_request_thread)] [INFO] GET request for '/.web/add/' received from 10.0.2.100 (forwarded for '10.0.2.100') using 'Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/137.0.0.0 Safari/537.36'
514a5fa4f318 [2025-07-03 18:45:00 +0000] [1/Thread-1 (process_request_thread)] [INFO] GET response status for '/.web/add/' in 0.207 seconds: 200 OK
514a5fa4f318 [2025-07-03 18:45:00 +0000] [1/Thread-2 (process_request_thread)] [INFO] GET request for '/favicon.ico' received from 10.0.2.100 (forwarded for '10.0.2.100') using 'Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/137.0.0.0 Safari/537.36'
514a5fa4f318 [2025-07-03 18:45:00 +0000] [1/Thread-2 (process_request_thread)] [INFO] Access to '/favicon.ico' denied for anonymous user
514a5fa4f318 [2025-07-03 18:45:00 +0000] [1/Thread-2 (process_request_thread)] [INFO] GET response status for '/favicon.ico' in 0.002 seconds: 401 Unauthorized
514a5fa4f318 [2025-07-03 18:45:08 +0000] [1/Thread-3 (process_request_thread)] [INFO] POST request for '/.web/add/' received from 10.0.2.100 (forwarded for '10.0.2.100') using 'Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/137.0.0.0 Safari/537.36'
514a5fa4f318 [2025-07-03 18:45:38 +0000] [1/Thread-3 (process_request_thread)] [INFO] POST response status for '/.web/add/' in 30.041 seconds: 200 OK
514a5fa4f318 [2025-07-03 18:45:38 +0000] [1/Thread-4 (process_request_thread)] [INFO] POST request for '/api/v1/authentication/login_challenge/' received from 10.0.2.100 (forwarded for '10.0.2.100') using 'etesync-dav etebase/0.5.1'
514a5fa4f318 [2025-07-03 18:45:38 +0000] [1/Thread-4 (process_request_thread)] [INFO] POST response status for '/api/v1/authentication/login_challenge/' in 0.001 seconds: 405 Method Not Allowed
514a5fa4f318 [2025-07-03 18:45:38 +0000] [1/Thread-5 (process_request_thread)] [INFO] GET request for '/favicon.ico' received from 10.0.2.100 (forwarded for '10.0.2.100') using 'Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/137.0.0.0 Safari/537.36'
514a5fa4f318 [2025-07-03 18:45:38 +0000] [1/Thread-5 (process_request_thread)] [INFO] Access to '/favicon.ico' denied for anonymous user
514a5fa4f318 [2025-07-03 18:45:38 +0000] [1/Thread-5 (process_request_thread)] [INFO] GET response status for '/favicon.ico' in 0.001 seconds: 401 Unauthorized

I'm not mounting any volumes so it's not a write permission issue on host machine.
Any advice would be greatly appreciated.
env: `

• ETESYNC_LISTEN_ADDRESS: "MY.CUSTOM.dedyn.io"
• ETESYNC_URL: "https://MY.CUSTOM.dedyn.io/"