MIC Mismatch after some days

TTN Network and Services The Things Stack v3
1

hi
for about 14 days i have a working dragino device (LDS01) on V3.
now i’m receiving a mic mismatch, i don’t change anything!.
i’m read here some problems with adding a device, but not after working for some days.

is this a problem with the device(soft) or the V3 stack?

thanks for any help

pat

2

now fill in the same app key again…it works!

how long?
the app key was not faulty(it was working for a couple of days)