Printing problem with Epson P800 & Windows10

Hello,
I have a printing problem with C1 (12.1.4), Windows 10 (1903) & Epson P800 (driver 6.74).
When I log into Windows 10 as a regular user, I cannot use custom paper sizes.
C1 always reverts to standard paper sizes

However, when I'm logged as an admin user, I do not have this problem.
This is also a problem I did not have a few months ago (with previous Windows 10 & C1 versions)

Last info : I do not have this problem with Adobe Lightroom

Has anybody already experienced the same kind of problem ?

Thx