Relays have become a pro feature in the last release. I tested them on netmaker.io SaaS version and they work but it defeats the purpose of selfhosting my VPN manager. You also need to have a good relay, for instance among GCP, Azure, Oracle and Vultr only the latter works because their VPS are not behind a NAT.
Netbird first of all is extremely resource hungry. In some occurrences completely hanged a 1 GB RAM VPS when I was testing. Even without trashing I had issues connecting many of my peers. It has to be said that it was surely my fault in some ways as netbird.io SaaS worked fine.