chat.sr.ht doesn't seem to show me any messages from when my client was
closed, both on senpai and the hosted gamja.

when someone messages me privately, the messages will only appear if
they message me again when I'm online, and when that happens, the last
message gets duplicated.

I can't view away logs of channels I'm in, even if I've been pinged.
tested on both Libera and OFTC.

It definitely should.

gamja will keep track of received/seen messages in localStorage. Make sure your
web browser is configured not to nuke localStorage when closed.

Until recently, senpai didn't fetch history correctly on launch. There are
still some rough edges but it should work now. Make sure you're using the
latest senpai commit. Ref [1] and [2].

soju will send the backlog to clients which don't support the chathistory IRC
extension, like WeeChat or Revolution IRC. Make sure to add a "@<client>"
suffix to your username on these clients.

[1]: https://git.sr.ht/~taiite/senpai/commit/6014ba12270933c74018f2914713ec6fb2ed4a77
[2]: https://git.sr.ht/~taiite/senpai/commit/24a84fad9bf5d53ef364d4711f6fb78e89b97a47

testing this again, it seems to have magically fixed itself. oh well!
I was using the latest senpai commit this whole time. I'll let you know
if this happens again, hopefully with a bit more debug information.