I keep an eye on the GWR▸ (Great Western Railway) advance bookings horizons page and I noticed it has not updated to 3rd Feb 2023 - but advance tickets are available on that date - I just bought one.
It looks to me whoever has to update this important page has not done it.
Cached page in browser ? just tried different device and browser, never used for GWR.
https://www.gwr.com/your-tickets/choosing-your-ticket/advance-tickets