Did you lap the receiver face to ensure the barrel is square with the upper receiver? It has been speculated not being square can contribute to early bolt failure. More Velocity usually equates to more pressure, AR Comp hasn’t been used as much as other powders.
Another forum member broke a couple bolts running IMR8208XBR with 107 grain SMK. His loads exhibited the same trait as yours so it is possible with the chamber heat plus suppressor your adding additional pressure/bolt thrust.
I’ve never used any rifle length gas 18” barrels and I don’t know if this gas system plays well with suppressors. Others on the forum have more experience than I do with suppressors and maybe they’ll chime in.
Another forum member broke a couple bolts running IMR8208XBR with 107 grain SMK. His loads exhibited the same trait as yours so it is possible with the chamber heat plus suppressor your adding additional pressure/bolt thrust.
I’ve never used any rifle length gas 18” barrels and I don’t know if this gas system plays well with suppressors. Others on the forum have more experience than I do with suppressors and maybe they’ll chime in.