I've had a similar issue several times.
We are riding a pre-planned route, we stop for a coffee etc.
When MyRoute re-starts on my Carpuride it asks "Continue navigation?" to which I agree and the MyRoute screen is visible but doesn't work.
I try by restarting and selection "Last Route" and that fails multiple times.
Eventually many miles along route I try again, "Continue Navigation", I accept and it asks to "skip waypoints 18 to 30?" I accept and things work as normal.
Luckily friends on ride (not on MyRoute) kept us on route.
Not inspiring!