One final annoyance with my @gotosocial#GoToSocial migration!

I implemented a split-domain setup, as wonderfully documented by @gotosocial here: docs.gotosocial.org/en/latest/
Note that #Mastodon also supports it, and documents it similarly here: docs.joinmastodon.org/admin/co

In both Mastodon and #GoToSocial, I notice that web clients FAIL to login with the account domain.

From what I see on the web server, the account domain receives exactly ONE request:
"POST /api/v1/apps HTTP/2.0" 404 146 "-" "Tusky/31.1 Android/15 OkHttp/5.1.0"
(This is Tusky, but Mastodon's app and others behave the same)

I tried to 301 / 307 redirect that endpoint (against @gotosocial's recommendation), but that fails in the same way (except I see the different matching code on the web server).

As a side effect, apps show my username as: at evilham at fedi.unchat.cat, instead of @evilhamEvilham , which is what I actually wanted.

What to do? >,<