I also have this problem. Can't respawn, but message says "you are dead".

Seems to be fixed for me now, I can now join and play like before, no problems. Thank you.

I found a way to get in to a server, you need to check the server information, I can't spawn in servers that have just "Dayz" as required version, but one's with "Dayz 114926" next to required version work just fine, so might be a server update thing, where they haven't updated all the servers yet or something. I added some images to illustrate what I mean.