Zigbee sensors randomly changing to "not available" after upgrading from CC2531 to CC2652

Hi,
after upgrading from CC2531 to a CC2652 based coordinator stick a number of my running sensors changed to “not available” (actually 5 of 30 sensors). This never happens during the time using CC2531.
Is this a “known error”?

regards,
Peter

After reconfiguring the devices twice they are all working fine up to today. No idea why I had to do this…