I'm not a developer and as I said is not easy and get errors also when try to fork and copy an extension. The issue will be also keep this updated because for sure copy a core extension and use it will never include updates so will create a potential security issue.
Sadly the sticky used in Flarum is not a full sticky because it doesn't work for my account that is always logged, that has already read the topic and need to see the topic on top and is not because the topic need to be unread to be sticky.
The only solution for me, at the moment is to edit the core code.
I'm not a developer.
I tried in the past to resolve the sticky issue but no solution has worked.
Someone created an extension that is not fully working and is not yet also updated since two years so this means a potential security issues or bugs can be present.
I tried to fork copy, etc but I broke always Flarum installation so this is not a solution for me, can be for a developer that maybe do that work without issues.
Anyway... will remain a mastery why sometimes I see the core extension code edit to be lost and reset, this was my topic purpose: try to understand why this happen.