At least one party in the conflict is generating enough interference on the ground to obstruct both GPS and GLONASS navigation in orbits passing over the region. Its loud enough to detect as soon as the region is visible (thousands of miles away). Source: we are operating a constellation of sophisticated GNSS receivers in LEO.
Hawkeye360 (a different operator of sophisticated RF instruments in LEO) detected GPS interference and geolocated it to Russian forces shortly before the invasion, but at this point it could easily be both parties.
Satellites don't need extremely frequent GPS fixes though, or do they? I think they can afford waiting half a revolution to correct their predicted location.
Hawkeye360 (a different operator of sophisticated RF instruments in LEO) detected GPS interference and geolocated it to Russian forces shortly before the invasion, but at this point it could easily be both parties.