I was testing out the seemingly inconsistent behaviour of "Reply to
thread" on a test list[1].

Sometimes my reply lands in the thread and sometimes it gets posted as a
seperate reply.

Anyway, I've tried to delete that list several times today but I just
get the message that says it may take a few minutes, and then nothing
happents.

1: https://lists.sr.ht/~adamski/testing

Hi there! There was a known issue with mailing list deletion that I just
rolled out a fix for. Can you give it another shot?

Seems to have worked. Thanks!