Not sure if this problem also applies to gitea, but it might explain why there is apparently only one¹ onion forge in existence, and it’s broken.

gg6zxtreajiijztyy5g6bt5o6l3qu32nrg7eulyemlhxwwl6enk6ghad.onion used to be relatively functional, perhaps because there was no clearnet variant, but it’s dead now.

¹ plz correct me if I am wrong. There used to be:

git.fuwafuwa.moe → git.fwfwqtpi2ofmehzdxe3e2htqfmhwfciwivpnsztv7dvpuamhr72ktlqd.onion
git.nogafam.es → git.hsdtecd4h2b5z732pvkg2yw3746epap4qusgvjjze6nhmfcdpz2suiad.onion
but they have been gone for quite some time now.