Extremely Odd Elytra + Trident Behavior

Ok- so In the video, I give myself Regen. 255 for 1000000 (infinite) seconds. Then, i enable my elytra, and with my trident (riptide), i simply look up. I get damage (for some reason), and then I get an "invalid mode packets" thing twice, and also my effects don't work. It shows them there, but you can see at the end i have regen still, yet my hearts are not going up.

Max file size weird thing, so i put it into a YT video
https://youtu.be/vt_CpYKcDmE