OK
Solved for me
From the battleeye FAQ:
When connecting to a BE-enabled server I get kicked with a request to restart my game.
This is happening because you permanently declined BE installation by clicking “Do not ask me again.” in the BE Launcher window previously. To fix this please go to the “BattlEye” folder in your game directory and double-click the “Install_BattlEye.bat” file to install BE.
Which is what I remember doing during the closed BETA...
Following
azakhi's instructions kind of worked. The first time it was like nothing happened and it still kicked me out.
The second time I followed the battleeye FAQ and just double-clicked on
Install_BattlEye normally instead of running as admin. It ran and I got the question of allowing Battle Eye to make changes to the computer etc. and clicked yes this time...
Then on launching the game I got this notification:
And all runs well so far. (I've been in the game and playing. Haven't been kicked yet).