I was experiencing the same issues with flyproxy - i was using a gitlab runner to run backups hourly so the slow down was eating into my compute minute costs on gitlab. After talking with support it looks like there definitely something up with flyproxy right now because with a direct wireguard connection my pgdump takes seconds (vs 10-15 minutes on flyproxy). I had to jump through some hoops but got wireguard setup on an ec2 instance to run my gitlab runner jobs and now the entire backup takes seconds and is working. I would prefer if flyproxy worked as it is much less setup for me but just thought id chime in here that a direct wireguard connection did fix the slow downs for me.