Bedroom AFCI trips are the most common callback for residential electricians, and they almost always fall into one of three buckets: bad connection somewhere on the circuit, an incompatible load (usually a cheap LED driver or an old dimmer), or a defective breaker. The code requires AFCI on bedroom circuits per 210.12 - so you can’t just swap it for a standard breaker to “fix” it without violating code. You need to actually solve it.
Diagnostic process: (1) Reset the breaker and turn off everything on the circuit. If it trips with no load, you have a wiring issue - start checking connections at every device and junction box, looking for nicked insulation, loose wire nuts, or parallel paths. (2) If it holds with no load, start adding devices back one at a time. When it trips, you’ve found your culprit load. LED dimmers are the #1 offender. (3) If you’ve eliminated the load and the wiring checks out, try a replacement breaker. I’ve had brand-new AFCI breakers out of the box that were defective.
One thing that trips up a lot of guys: AFCI breakers don’t like shared neutrals on multi-wire branch circuits. If you have a MWBC feeding a bedroom and you put an AFCI breaker on it, you’ll get nuisance trips because the other circuit’s current is flowing on the shared neutral and the AFCI interprets it as an anomaly. Dedicated neutrals only on AFCI circuits.