22.22. hrm pro+ connection/data during workout

I have a problem with heart rate during workout. hrm pro + connect, and it shows it is connected. Watch optical sensor is working (not sure if previously was also) but hart rate readings are totally inconsistent. There is a lot of missing data.as a result, the kilometres travelled are also missing.

Same strange behavior have my wife, and co payer on same badminton session.

This one for me is quite a big problem, since it is a primary function of a watch.

HRM-Pro Plus
Software: 8.9
Battery Status: OK
ant+ connection.