I forgot to update here, but my problem recently got resolved. It was an issue with e-licenser. So, I updated to latest soft e-licenser, requested new activation code for Padshop (thanks to great support from Steinberg team) and then activated it again freshly on the soft e-licenser. Since then, Padshop is working is nicely so far in FL Studio and Windows 10. I don’t exactly remember about using it on 20.6, but I believe it should work without any problems.
Please note that I do not have the USB e-licenser.
Wish you all a happy and prosperous New Year! 