Various fixes

[Maxr1998]

:star2: Description

I discovered a few bugs while debugging an issue in this library today. Please let me know if I should create separate PRs for these. All changes are mostly self-contained, but the commits touch similar parts of the code and thus partially depend on each other. I wrote descriptions for each issue inside the commit messages. Please don't hesitate to cherry-pick or modify this PR as you wish.

Hopefully, these changes can be upstreamed, since that would be better than continuing to maintain our fork.