There's a major bug in Under-50 BGs where all stats, resistances, damage values, and heal values,
are being reduced by ~60%. I haven't seen an official Known Issue thread about it, so starting one here.
Here are my stats outside of BG (28k Health, 1600 Stamina Recovery):

But in an under-level-50 BG, I have 10k Health, and 194 Stamina Recovery.

You can see that stats are impacted across the board.
This makes breaking free more than once impossible. This bug has been active for all of Update 49.
This is impacting everyone in under-50 BGs and making every game a terrible slog.
I think part of it is because of item leveling being busted:
Out of BG, My staff has 965 Weapon/Spell Damage:

In BG, my staff has 370 Weapon/Spell Damage:

Mundus Stone values are also reduced in BG, whereas some are usually slightly increased for low-level characters.
Higher level characters seem to have higher stats and be impacted less. It feels like it's treating my character as level 50, and reducing my armor/mundus/passive bonuses because they're associated with my true level, not their level 50 value. Previously, these buffs worked fine and would even get boosted for low-level characters (such as max health, recovery, etc).