Can't reply to Kbin post for some reason.

[kotking]

I made Thread on Kbin and wanted for some people have ability to self-promote themselves from Misskey.io directly. So I quoted message and asked them if they would like to participate by simple reply. https://misskey.io/notes/9ib8787c9z . After some time people did answer, but I have 2 people report that they get error when trying to reply. I confirmed myself https://imgur.com/a/3wjEcCb and can't reply as well. So is this Misskey.io limitation to old posts or there is an issue to resolve? I would like to know for any future endeavours as you can't make Threads from Misskey.io on Kbin.social but you can reply to Thread, so with some hoop jumping people can interact with forums from their Misskey instance if they wish. I really hope this can be resolved and error don't give me concrete information what is wrong (it's not issue with de/federation as the most obvious one).