Field condition between different user blueprints

We have different blueprints for different roles.
admin role get’s the regular blueprint, editor get’s the restricted blueprint.
In kirby 3 we have been showing a custom tab section if isvisible: true.
isvisible on the other hand is only available in the blueprint for the admin.
So the admin controls what the editor is seeing.

Now… in kirby 4 it seems that the editor role only loads the page-data which it needs through the its restricted blueprint. So isvisible is never true, as it is not available.

Am I missing something?

So…
When I do

when:
   isvisible: 'false'

false as a string, it works?!