Impossibilité de configurer les interfaces

Hello,
That's certainly a silly question.
In the recent past, I created interfaces for which I had full rights. I was able to adjust the position of fields, their size, etc.
Today, still with full rights, I've gone back to the same bases and recreated interfaces, but I'm no longer able to modify the layout, size, etc. of the fields.
It's very annoying...
Here's a short film : https://youtu.be/n4yvkNTfv9c
Thanks in advance,
Erwan