Difficulty spawning into vehicles at start of round.

It is a problem, I encounter the same on PC. My guess is it has to do with server latency. The tank still show as available on your userside, while somebody with a quicker connection/mouse finger already selected it. So you select it also and while it shows as being selected by you, the game is not able to sort out that you were to slow ending up in a freese on your screen/no spawning in the selected vehicule.