Heart rate graph

Hi all,

I am using Fenix 8 with HRM Pro plus. On Fenix 8 I have turned off wrist sensor (because of dry suit). When i start diving activity I get notification, that ext. sensor was connected. After dive I get notification, that data are collected. So everything looks good, but when I go to Garmin Dive app there is nonsense in heart rate graph, BUT when I check it on website the graph looks good. Also when I export .fit file the heart rate data are not correct.

Can someone please check?