I want to improve my godbridging so that it is "clean". The problem here is that blocks often despawn and then I fall down. I play version 1.16.5 with Optifine
Do you play on Java?
Then go to an MC server, preferably with 1.8.9
I would recommend the Minesucht.net or Gommehd.net server to practice.
If you're playing the Windows Edition, it's normal for the blocks to bug.
Possibly there's also a server for the Windows Edition, where this works. I don't know anyone there.
I play on the Java Edition and for practicing I use MCPlayHD. The problem also occurs in single player
What is MCPlayHD? A server?
A server known for its bridging exercises
Try other servers. And with the 1.8.9