If you think about even the spring “catching” on something, it should still compress more than enough to lock charging handle back. You compress it quite a bit when installing locking pin right? So it should compress an extra few mm’s to seat handle locked.
You may have a physical obstruction, burrs on bolt, inside recoil tube, bolt misaligned and binding.
I smoothed out my bolt(s) exterior with very fine emery cloth and deburred tube interior with a 12 gauge shotgun brush. Another physical trait of bolts in tubes is too small a bolt in tube, and when under pressure loses parallel alignment, tilting and binding. I would think doubtful, but that is physical properties of items in tubes binding under pressure and resulting in being not parallel in direction of travel.