Failed to send new fence points in Geofence

It seems that “failed to send new fence points” has reappeared in Plane 3.8 beta causing loading of Geo-Fence points to fail. The problem may be related to what occurred several years back.

I have Mission Planner version connected to the Solo 3DR.
After I have created geofence and return location point I get a following message during Upload:
"Failed to send new fence points System.TimeOutException: Timeout on read - getFencePoint at MissionPlanner.MavLinkIntervace.getFencePoint(Int32 no, Int32Total) etc.

I have the same problem.
Is there any suggestion about this issue?