I did the Win10 upgrade to a Win8.1 setup. Kodi V15 was installed with IPTV Stalker and PVR Stalker both working fine.
I checked out both after the upgrade completed and no problems whatsoever, no settings changed anywhere.
I agree with those that advise reinstalling Kodi, but it could be some combinations of settings, video adapter, etc, could be holding things up under Windows 10.
I have to say Windows 10 has done the best job of making 'upgrading' smooth and painless of any previous version...and I have been with Windows since V3.1.
System:
AMD Phenom II X4 955
32GB Ram
NVIDIA GeForce GT 440 (I think a 'legacy' card by now, LoL)
Monty