Re GPS malfunctioning. Were you within scope of this:
Notification of GPS jamming exercise: Stanford Training Area (STANTA), Norfolk
Dates: The exercise will run over the period 03 Feb to 14 February 2020.
Times: 09:00 – 19:00
Location: Jammers will be placed Stanford Training Area (STANTA) within 3 km of WGS84 Lat/Lon 52°32’30”N 0°43’52”E (British National Grid reference TL85305 97261) affecting GNSS receivers at the following heights (AGL/AMSL)/distances:
2m AGL: Receivers with clear line of sight to the jammer location to a maximum possible range of 23km.
25m AGL: Receivers with clear line of sight to the jammer location to a maximum possible range of 23km.
70m AGL: Receivers with a clear ling of sight to the jammer location to a maximum possible range of 32.3km.
5,000ft AMSL: To a maximum possible range of 55km.
10,000ft AMSL: To a maximum possible range of 55km.
20,000ft AMSL: To a maximum possible range of 55km.
30,000ft AMSL: To a maximum possible range of 55km.
40,000ft AMSL: To a maximum possible range of 55km.
Frequencies:
GPS L1 band (1575.42MHz +/- 15MHz)
GLONASS L1 band (1597.55MHz – 1605.89MHz)