Being left being on RGT

Hi all
I haven’t been exploring RGT a huge amount yet but when I have signed up to join a group ride I get totally left behind at the start.
I’m on a Wattbike Atom. I wait at the start with the other riders, watch the event countdown clock , begin pedalling in advance then watch while the pack disappear up the road!! It seems to take a good 10 secs for my avatar to start moving even though I’m pedalling.
I then have to bury myself to catch up. Any ideas why there’s a delay for me at the start line?? It’s putting me off using the platform. Thanks