Fly API error on release

Seeing this when releasing tonight.

==> Creating release
Error Post “GraphQL Playground”: http2: server sent GOAWAY and closed the connection; LastStreamID=2147483647, ErrCode=NO_ERROR, debug=“”

I started seeing this after changing my fly.toml from being a multi-process app to not being a multi-process app. Is this known to cause problems?

Also, the load balancer is only sending traffic to one container, even though I have 8 up and running (via fly scale count, not autoscaling)