Before I start, I wanted to point out that there was a 48-hour downtime after this update on realms.

There are way too many bugs to be named after the 1.16.100 hotfix in minecraft realms, but here are some listed
-Intense server lag (Most likely causing some of the other listed bugs down below)
-Failure to deploy elytra
-Taking fall damage before hitting the ground
-Taking fall damage when falling into water
-Invisible chests, occurring with half chests where only one is invisible, and when opened, it may crash the server and revert to when you first logged on (Which may have disabled achievements because I tried to do one this morning but it didn't work).
-Longer load times in the Minecraft menus when showing available realms and when trying to connect to a realm
-When building up while holding jump button and build button, the block may lag and take extra time to place, pushing you off of the stack of blocks you were building on top of
In conclusion, server lag has devastated our Minecraft realm.