Does anyone know if the how the ADS-B uncertainty measurements interact with GPS spoofing? Often when you look at these maps you see a donut around Kaliningrad

Does anyone know if the how the ADS-B uncertainty measurements interact with GPS spoofing? Often when you look at these maps you see a donut around Kaliningrad - could it be that there's wide area jamming, and then localized spoofing more directly around Kaliningrad?