I can confirm this and other strange things are happening in the script editor for 20.
If I copy and paste in the main script window it appears correct but it is not really working.
Look in the pop-out window and it is not there or something completely different happens which destroys the script.
It may look Ok but it isn’t.
Look at this simple example where I have copied and pasted a small piece of script.
Versions 6.5 to 22
Dell XPS- i7-6700 @ 3.4Ghz, 16GB ram, GeForce GTX 960 (2GB), Windows 10
Dell Precision M6800 - i7 4700MQ @ 2.40GHz, 16GB RAM, AMD FirePro M6100 (2GB), Windows 7 64bit