Cannot hide some labels in Screen Customization

Hello,

We use Projeqtor in v8.4.2 on Firefox (usually last version)

We use 2 instances of Projeqtor updated at the same time.

On the Screen Customization Panel, we encounter a problem on some elements (here, example on Project screen)

On one, "code contrat" is still visible even when the option Hidden is checked in the customization (We even have the green acknowledgement that it worked)


On the other, it is "code projet" that is unable to be hidden


I even checked in Project if there was someone that wrote something in that line (on archive mode) and nothing was found (on either instance of Projeqtor)


Could you help me understand where i made a mistake ? or where i should check ?
Thank you