Two of my favourites from over the years.
1. Used to do work as QA for video games. One game (contractually can't name, even if it's been a decade), had a bug where if you walked over a specific spot on the map, you would get stuck. There was no geometry nearby you'd be stuck on, there was literally nothing making you stuck. Tag it in the bug report system, and over the next 3 weeks the devs would bounce back asking if it was fixed. Every single time, "nope, you still get stuck". The dev that modeled all of the collisions and geometry for the map even took the time to decompile the entire map looking for goddamn anything that could be the issue. Final fix was to slap a big ass rock around the bug so you couldn't even get close to the spot. Many laughs were had across the whole QA team when we discovered that fix.
2. Built a website for a client. Basic ass shit, they couldn't afford too much. One feature they asked for (which took no time to impliment) was to add a parallax scrolling effect to various items on the page. Worked like a in all browsers, except one. For whatever fucking reason, IE would lag and give an extremely choppy animation. Piece of shit, can't mark it as "Won't fix, IE is just trash" because clearly the animation worked to a degree, and the client even noted it work perfectly on one page. Hours of googling later and cursing, the fix was quite possibly the most jank shit I've ever seen. For reasons beyond human comprehension, the parallax would work perfectly in IE whenever a Google Map was on the page. Ended up hidding a 1px×1px map on every page.