For Android users, you may encounter an issue wherein your wireless bluetooth headphones/earphones disconnect once a call starts. Here's one thing to try for troubleshooting
1. Go to your phone's Settings > Location
2. Click on App Permissions
3. Click Chrome
4. Click See all Chrome Permissions
5. Click Nearby devices then Allow.
Once you click Allow, close the Chrome app (from your recently open apps pane) then open the app again and try to make a test call.
If the issue still persists, do contact support on the SeriousMD app.