Whenever a Trampoline is placed between or surrounded by 3-4 solid blocks, crouching down on it will cause the Trampoline to un-render itself. This isn't the case when a transparent block like several leaves or glass blocks are next to it.

Here's a video showing it:
https://github.com/dayofpi/super-block-world/assets/160932138/27182b3a-12d0-4d64-88f7-4cada4664ad6

Here's some screenshots to better depict it:

MC Version: 1.20.1
Forge: 47.2.0
Super Block World Mod Version: 0.0.8-1.20