I have experienced a few times now that text I copied from my old website and pasted into Cataloge/Information confirmed saving. But when I checked it, it was always completely gone.
I think I found the reason - if there is no "Enter" at the end of the text (which is not visible), it is simply not saved.
Could possibly be a bug in the program?

Do you have instructions for reproducing the problem?

I tried to visualize it with screenshots, but have some problems to upload here 4 pictures.

Picture 3 + 4

I have seen that unfortunately the titles of the images are not visible here:

1 Quack w_o enter and stored

2 Quack w_o enter after store

3 Quack with enter + store

4 Quack with enter after store

Unfortunately my screenshot never shows the green bar at the top "Saved".

I'm in the demo and I can't reproduce this. No matter if I type or paste in a description. It saves properly and is there next time I load the product.

Are you sure this is not a browser add-on issue? Did you try another browser without browser addons?

It looks like the cause of the error is actually one of the addons from my Firefox 109, because when I try Brave, in which I have no addons, the effect does not occur.
Then at least we know it's not LC and since I know the error by now, it's more easily avoidable than now turning off all ~15 addons individually and checking each time in LC.