I'm not sure I understand your question correctly; did you use a HRM-Tri or HRM-Swim during swimming or not? The FR935 only searches for stored HRM data if you started the swim with a HRM-Tri or HRM-Swim connected. And it would be strange if no data were available in that case. If you have a HRM-tri or Swim, but don't want to use it during swimming, make sure the HRM is not active and not connected to the watch before the start of the swim. Or disable the HRM in the settings -> Sensors menu. If no HRM was active/connected, the watch will not search for stored data.
No i didn't use any HRM tri or another sensor during my swim. I just want to skip to tell my watch that i don't want to search för any hrm data. I think that it was possible on a older watch to change that in a setting
The 935 will still search for stored heart rate data even if a HRM wasn't connected at the start of a swim activity. I've put my HRM-Swim on underwater before where the 935 wouldn't have picked up a signal and it still automatically downloaded at the end.
If you have an hrm-tri or swim synchronized with the watch, it will always looking for hr data. And, as far I knew, there’s no way to disable the searching.
I stand corrected. I had no stored HR the other day on a few occasions because - I assumed - I had jumped in the water too quickly before it had connected to the watch. The FR935 didn't search for stored HR after the swim. Now I suspect the HRM-Tri is defective (the battery was recently replaced).