Extension panels limited to 20

Hello

For a long time I use Photoshop with extension panels and customized my second display with most of them

Since a few days ago, most of these panels don't show up and when I try to set them in the working area, I get a message sayng theat "only 20 extension panels" can be open simultaneously !

I used to have ver 20 panels visible at the same time

How come that this problem hapens ? Is this a bug in a recent update of Photoshop ? Is there a way to fix  it ?

Thanks for any help

Have a good day