@tekolote Thanks, that was helpful. I think I've made progress but still not 100% there. When I go to my sliding URL/.well-known/matrix/client I get the return as expected:
{"m.homeserver": {"base_url": "https://bridge.domain.co.uk"}, "org.matrix.msc3575.proxy": {"url": "https://sliding.domain.co.uk"}}
If I go directly to https://sliding.domain.co.uk I get a 404 error.
When configuring Element X, I enter the URL as https://sliding.domain.co.uk and it detects I've got sliding enabled but doesn't get past that first configuration screen. Looking at the sliding logs it has the following:
21:14:48 INF Received connection from unknown access token, querying with homeserver
21:14:48 INF c= duration=0.000 path=//_matrix/client/r0/account/whoami size=0 status=301
21:14:48 INF c= duration=0.000 path=/_matrix/client/r0/account/whoami size=19 status=404
{"level":"warn","error":"/whoami returned HTTP 404","time":"2024-03-23T21:14:48Z","message":"failed to get user ID from device ID"}
21:14:48 ERR failed to get or create Conn error="HTTP 502 : /whoami returned HTTP 404"
Any ideas? ( @JEZBRO if you're able to help too, appreciate the offer!)