Another bug (that I think is well known but still bears remembering) is this one. I stumbled upon it by accident when I was looking at the personal feeds on my profile. The first post I had made disappeared. Apparently, it's a bug where the nth post of the personal feeds doesn't show up. So, I think it's the 6th or 7th post. Each time, the 6th, 12th, etc or the 7th, 14th, etc post disappear from view. It's a bit frustrating ngl.
Place where the bug happened: my own feeds (https://kisskh.at/profile/chirisu/feeds) and I think it's the same for everyone's personal feeds, not just a quirk of mine. Someone told me on the public Feeds that it's a known bug that has turned into a quirk of the website.
Bonus: The Coins page's FAQ says that only 100 flowers can be sent to any celebrity's page in a week, but that has since changed to 300 flowers. This could mislead some people into donating less flowers per week, who knows. (https://kisskh.at/coins)
If I come across other bugs I'll make sure to add them to the pile here. Happy bug fixing!