Those are offline malfunctions. Here is the post describing what they are.
They are occurring for all 345Mhz sensors periodically. It is not occurring on PowerG sensors that I see.
The thin white antenna in the panel must be checked in order to troubleshoot. It is very likely the cause. It must be routed out the back of the panel to ensure the best communication from 345Mhz sensors. It cannot be left inside the panel.
Offline malfunctions can resolve themselves. The cause of the issue is missed supervision signals, and when the panel receives a subsequent supervision signal, that lets it know the sensor is functioning and the offline malfunction goes away.
Please see the prior answer linked below for the prior description of this.
Have you checked the antenna yet? It is the cause of this kind of behavior on an IQ Panel 2 about 99.99% of the time.