Call of /oauth2/registration error 400

[Tealk]

Hello,

I noticed this problem because I wanted to try out Element Admin, where I get a 400 when I enter the domain of my instance. When I check the MAS log, I see the following message:

Oct 21 21:20:37 synapse mas-cli[892637]: 2025-10-21T19:20:37.141974Z WARN http.server.response GET-3396421 - "GET /oauth2/registration HTTP/1.1" 405 Method Not Allowed "Mozilla/5.0 (X11; Linux x86_64; rv:144.0) Gecko/20100101 Firefox/144.0" [polls: 0, cpu: 0.0ms, elapsed: 0.0ms]

all other endpoints work:
/authorize
/oauth2/token