Since 2023-12-25 GPSJAM [1] reports high level of GPS interference over southern Baltic and half of Poland. NOTAM [2] has been posted without further explanation.
[1] https://gpsjam.org/?lat=53.39072&lon=19.51357&z=4.5
[2] https://metar-taf.com/pl/notam/EPWW-C1142-23-70689986