Actually using 8.7.9, but I noticded this a few versions before , too.
Way to reproduce at my toaster (RigManager not connected) :
Browser mode, switch between rigs using Rig left/right buttons.
STORE is always on.
After selecting an effect, the STORE button´s LED turns off. EXIT : STORE is lit.
Pressing STORE, then replace : STORE LED off.
Then switch to next rig and back, STORE LED is on again.
Bug, feature or am I doing something wrong ?
Best regards
Bernhard