GXP is pretty crap anyway - if you wanna run a SRAM crank use the 2mm adapter to run a proper 24/24 shimano BB.
Unfortunately a GXP spindle + 2mm adapter on a 24/24mm BB is quite bad too.
If I remember well from a Hambini video.
The issue seems to be a patent one, that only Shimano can put a 24mm floating axle between two bearings.
And SRAM came with GXP, that locks the left bearing, and as a result takes all the lateral load, and fail sooner.
The best solution I found was to put a BB Infinite shell. And easily change the bearings.
The bearings were lasting longer, but still the left one was failing early.