The partition config for ZBOSS is set in different locations in NCS. For us this worked out magically in the past because the values that were written have been the same in all locations.
With the "new" Zigbee R22 add-on the size of the NVRAM partition is set statically to 0x8000. However, in the old NCS for nRF52833 it has been set to 0x4000. Updating to a larger NVRAM partition (partition start is moved forward) destroys the whole content as it cannot be read anymore.
Old: (differs between SOC_NRF52833 and !SOC_NRF52833)
https://github.com/nrfconnect/sdk-nrf/blob/v2.9-branch/subsys/partition_manager/Kconfig#L104-L114
New: (0x8000 for all SOCs)
https://github.com/nrfconnect/ncs-zigbee-r22/blob/main/subsys/Kconfig#L394-L396
If that is intended, I'd propose a big big warning in the upgrading guide as this will reset all devices.
For reference: I'm updating from NCS v2.5.2 to NCS v2.9.1 including the new add-on structure.
Best regards
Patrick
