You can call LMT, but I imagine their answer would be send your rifle and ammo for testing, and likely zero warranty since it functions fine without the suppressor. Ive owned over 30 semi auto 30 cal guns, majority suppressed, and never had an issue with accuracy or anything other than POI shift except for the one that smoked my SDN6 due to the defective brake, which they fixed, and it was flawless after. Most of them were severely over gassed as I hand load and shoot to 1100+ yards, which requires some hot rounds to make consistent hits, and all that did at worst was chew up brass or double feed here and there, because by the time any adverse action has occurred, the bullet has long since left the barrel.
If you dont want to send it to LMT, best bet is put your can on a different rifle, or try another can on your rifle, and see if the problem resolves itself. If by some chance, multiple suppressors cause the issue on your rifle, or your suppressor AND muzzle device work fine on another rifle, there are ULTRA RARE issues such as barrel threading issues or damage to the bore causing deflection, but generally your suppressor would also show issues or at least a hit.
Velocity wouldnt be a factor unless youre running sub sonic since 30 cal bullets often exceed 3,000 FPS in magnum cartridges