Hi,
It appears that this recently closed bug is recurring:
Here is a video from today showing how components in a list are disappearing and reappearing, in the cloud editor:
https://drive.google.com/file/d/1k6z992TXUV2tzs_6N5WzV4rCy_5-UUXd/view?usp=sharing
Please let me know if you need anything else to help debug this.
Best,
Barton
I have reopened it, please let us discuss it there.