I was in a single-player survival world (difficulty normal) and was flying around with my elytra. After a while, my computer stopped rendering the chunks and I was almost stuck in an unrendered area but was able to pull out very quickly. Afterward, my firework effect was going constantly, and I threw some Gapples into the void to see what would happen. The gapples then started duplicating right next to me infinitely, and every other item repeated this. About 30 seconds later, my game crashed. When I loaded up the game again, the chunks were rendered, but I still had the duped gapples. (If needed I will perform this again, sadly I didn't get a screenshot due to my game crashing) 

Update

Below is a picture mid-frame of the gapples dropping

Everything past the line is void

The firework effect also remains infinitely

The Picture was taken on a 1.19.2 independent server, but can be redone on a singleplayer server if needed.