Mouse wheel functions doesn't work after changing tabs

Forgot if it was the default, but changing tabs / project files is mapped to “‘page down’ & up” for me.
Somehow, every after changing tabs, anything mapped that needs the mousewheels’ input doesn’t work.

By tabs, i mean these:

image


image
^ All of these functions found in the above screenshot are affected.

I have to press the ‘LMB’ somewhere in the canvass first before the mouse wheel behaves like normal again.

Just in case, Any issue/setting i have that might actually be causing this?

PMNG ver. 7.2.7.0