LOL.
That is the older DPMS style forward assist. It's supposed to be like that. Notice it's forward on the upper and one piece with the shell deflector? The bolt carrier is supposed to be smooth with that type. That was how all DPMS .308 rifles were made for a long time. My older generation factory Bushmaster (rebranded DPMS) is made like that too. The forward assist works off the ledge on the bolt carrier in that location. However, forward assists are not really necessary with a .308 AR anyway due to weight of the bolt carrier slamming home and greater buffer spring tension.
Newer generations of .308 "AR-10" type rifles have trended toward the Ar15 style forward assist toward the rear of the upper and separate from the shell deflector. This requires forward assist serrations on the bolt carrier.
If you look on parts websites for an actual DPMS branded .308 BCG (not just DPMS compatible), you will see they have no forward assist serrations.
Personally I would prefer if they would delete the forward assist all together on .308 ARs and just have a shell deflector and port door. Looks better, less weight, etc.