Group aggregation lost after udpate or clean-cache

  • Platform information:
    • Hardware: Intel X86_64 / 16 GB Ram
    • OS: OpenSuSE Leap 15.0
    • Java Runtime Environment:1.8.0_222
    • openHAB version: 2.5.5
  • Issue of the topic: I use Paper UI for all configurations. I have several groups which have aggregation functions configured. Since 2.5.0 every update erases the group item Base Type and Function. Base Type is always “none” after update.

Settings read from Rest API:

“groupType”: “Switch”,
“function”: {
“name”: “OR”,
“params”: [
“ON”,
“OFF”
]
},

The following errors appear in the log after starting openhab when it was updated:

2020-03-20 03:01:29.954 [ERROR] [e.internal.items.GroupFunctionHelper] - Group function 'AND' requires two arguments. Using Equality
 instead.
2020-03-20 03:01:29.954 [ERROR] [e.internal.items.GroupFunctionHelper] - Group function 'OR' requires two arguments. Using Equality
instead.

It usually takes two starts after an update to repopulate the cache for a working config.

The Base Type and Function fields are not repopulated, no matter how often I restart openhab. The Item settings are not available in the Rest API.
It took me quite a long time to find out why my group rules did not work and I did not see the number of open windows in the official app.