I've not come across this bug before. It's happened to me twice over the past few days and it's a serious one.
I am using Views (not Blocks) and have both classic and block editor enabled in Toolset Settings.
For no reason, when updating a Content Template (one previously saved and edited), the contents completely vanish and it becomes empty with no way of retrieving the content.
I can't replicate this yet... and I don't know why the CT emptied itself randomly. It was a CT originally created/edited using the block editor and then I refreshed it and reset it to use the Classic Editor. I then edited as normal and saved many times. I am guessing somehow the resetting is kicking in again?
At the time it last happened I was editing/saving a view in a different tab, then switched back to the CT tab. It looked like it wanted me to save it again and it emptied when I hit Update.
I appreciate there's not much you can do if it can't be replicated so will see if I can replicate it.
This one will be difficult to diagnose given that there isn't a clear replication step. I do however know that if you are using a content template with the block editor and then switch it to the classic editor you will lose your data. However there is a warning about this before it allows you to change the template styling.
I would first try to rule out a plugin conflict by temporarily disabling all the non-toolset plugins and checking to see if the problem still occurs.
Once there are clear replication steps then you can let me know. Also if this only occurs with one particular template then I would suggest that you try to remake that template as well.
