Resume Oruxmaps in Trip Computer with HRM

On my today's Biketour I had a very anoying problem. I used Oruxmaps (4.4.1) in Trip Computer view and was logging my trip with BT heartrate monitor. I switched to the SMS-app to write a message. When I came back to Oruxmaps it showed the actual speed and elevation, but fields for time, distance etc. were empty. I thought that Oruxmaps stopped logging and therefore I wanted to start a new track. But there was only the option to stop logging in the menu. So I stopped logging and wanted to start a new track with HRM. It started, but Oruxmaps couldn't connect to my Polar-Belt anymore. After some seconds he told me "Bluetooth connection closed". I closed Oruxmaps, disabled Bluetooth - same behaviour. I restarted my phone, but nothing changed.

I'll try to reproduce the problems in "laboratory conditions".

Dear
Berni