Dual GPS units...tons of errors, but flight rock solid?

ArduCopter Copter 3.2
1

Hi all,

Does anyone know why I get this? Tons of GPS errors in forward flight, but no real impact on flight characteristics. Did a 35 minute loiter right afterwards…no GPS errors. Only thing changed was battery packs.

Dual M8N’s, Pixhawk clone, Powered from PM, arducopter 3.2.1. GPS count - see attached.

2

Log files would help. Both tlog and dataflash.
EM interference affects GPS. Perhaps when you replaced the battery you moved the cables and resolved the issue or a problem with the first battery?
Thanks, Grant