ᐅ Grohe toilet flush tank fills with water too slowly

Hello,

my toilet cistern fills with water very slowly. It takes 30 to 60 minutes to fill completely before I can flush again!
I have the Grohe Dal toilet cistern.

Does anyone have any advice?
Thank you!

Is this a new feature or a newly installed component?

That can be adjusted. I assume it’s a concealed installation. You need to remove the actuator plate and look inside.
There is a shut-off valve inside the box that might not be fully open.

Check everything. If in doubt, contact your plumber.