[Shark6]

GPS date rollover is to blame:

Synscan versions among many other systems relying on the 1980 being 'Zero" year for GPS systems will not handle the rollover well........ A new Epoch signifying the beginning of another 1024 week cycle began a couple of days ago to the chagrin of many systems....
READ HERE:

https://techcrunch.com/2019/04/06/gp...ght-get-wacky/