Connection to Zwift just after the start of events

I use Zwift in my Win10 64bit desktop together with my Android companion. This setup works and during normal rides I do not have any problems. but at every big events like TdZ stages 1 and 2, few seconds after the event start tI lost the connection to Zwift. This happened in the last 3 events I did participate.
This is very disappointing, especially if you connect 20min before the start, warms you up and just after the start you see all riders passing you, while I stuck some meters after the start line.

The same problem @ Stage 1 and 2; Win10 Home 64bit, Android Zwift Companion; NGeco Powermeter, Polar H7. Losing connection to BT devices after start; would be nice to have to possibility to search and pair devices in the Companion App.