Nightmare Raid - Missing Role Force Charges

Gauln_01

Was fighting Mangog until he got 10 charges and went into enraged. Block a hit and got staggered.

After that, I no longer seem to do additional damage with the Force Charges, not sure if the Force Charges were staggered, resulting in no new Force Charges being gained even after completing missions.

Goodlordbird

Which champ & role boost are you using?