Loading bar appears after placing every sign.

Building @silentwisperer Mob farm using signs to stop the water flow. Kills PS5 Gameplay with a silly loading bar that pops up just after placing a sign. It can take several minutes to place one sign. I managed to lose several hours wasting time placing signs and discovered that fence gates did a better job.   
This is a single-player survival mode game on Bedrock. Not on a server.
See What I mean here:
https://youtu.be/ks0ngCtzY2I