Hi,
I have noticed that there seems to be a bug affecting some, but not all players in under 50s battlegrounds since U49.
I have not encountered the bug in regular over 50 battlegrounds.
What is happening is that character stats are being massively reduced upon entering a battleground - far more than can be attributed to the removal of CP and the activation of Battle Spirit.
I took two screenshots of my characters stat sheet, one in Icereach (Under 50 Cyrodil campaign), and one in an Under 50 battleground, for the same character, with the same gear etc. and have attached them here, and you can see the battle spirit is active in both.
In some cases, stats are being reduced by over 50%.
Under 50 Cyrodil:

The under 50 battleground:
