When someone finds a problem, you raise a bug with reproduction steps, then either fix it or put it in the backlog. Even if it is a document bug. This way anyone - even people not in that chat - can find it.

This is normal operating procedure everywhere: write stuff down. It was how everyone did things before chat was digital, and how they do now too.

If people are relying on searching chat history for how to fix things or get things working, then you are working at a cowboy outfit where quality must suck. I am not saying google the ideal here - I have no insider knowledge there - but fuck dude using chat history to document and maintain your system? Jesus.