This bug is similar to T170087 in the fact if you die before you spawn you will be unable to spawn again until you rejoin the server. This bug occurs either with Friendly fire, or with Enemy fire.
The server will not register you as alive, and you cannot respawn. This normally happens when you are spawning at a base that is being taken by the enemy and they kill you before you manage to load.
Get killed a few times while spawning in, and it'll glitch to this eventually.
I posted the video of it on the other bug repor that we closed
https://www.youtube.com/watch?v=jXCEckJSs-s
The only way this occurs is if a base is under attack and you respawn at the base while it's under attack. I don't know if it has to do with losing the base, or if it has to do with the game sync thinking you're at the map and able to respawn when you can't.