Put about 100rds through a Sig Mosquito, earlier. Their reputation for cycling like shit seems to be well deserved.
Were you using high velocity ammo? They are currently saying the GSG Firefly (same gun, different name) is for HV ammo. Read product description:
https://www.classicfirearms.com/ati-gsg-firefly-hga-22lr-black-gerg2210tff/