My shiny new subpanel has a shiny new Eaton BR AFCI/GCFI 15 amp breaker feeding two receptacles.
I plugged a rather disreputable looking 12-amp electric mower into a receptacle with no other load. The breaker tripped. The breaker passes its own test button and a GFCI outlet tester plugged into it is happy. The mower works in another outlet that is a 15 amp outlet on a 20 amp circuit.
A heat gun plugged into the same outlet is perfectly happy; of course, it's probably not drawing anything like 12 amps.
Is this a question of transient load, and if I wanted to be able to run such a thing would I need to upgrade the wire to 12 gauge and the breaker to 20 amps?