Trouble with diy wiring in basement room with afci and ceiling fan
One thing that will cause AFCI's to trip also happens to be something that will cause GFCI's to trip: crossed neutrals. 

As you may know, all grounds are just basically a cloud of grounds - all grounds coming out of a panel can generally be mixed together, even if they are from different circuits out of that panel.   Back in the day, people sometimes thought the same thing of neutral, which was never true.  But it happens all the time where someone "grabs the nearest neutral" and that happens to be a neutral from a different circuit.  Or neutrals from 2 circuits have been tied together.  This mistake was undetectable; neutrals don't have breakers.

Now GFCIs and AFCIs don't like crossed neutrals, so it matters. 

GFCI and AFCI will tolerate this situation as long as there is 0 load on the miswired part of the circuit (or both circuits if the neutrals are tied together on 2 circuits).  However when you add load, some or all of the neutral current "goes the wrong way". GFCI's are super sensitive to this, AFCIs less so, but will still trip. 

Of course, it goes without saying that AFCIs don't work on multi-wire branch circuits (MWBC).  If in the panel, your AFCI "hot" is feeding up into a /3 cable with another hot fed from a different breaker, that is an MWBC. Safety requires you fix it: Get a 2-pole, 240V, handle-tied breaker, and land both hots on opposite sides of that breaker.  The AFCI versions of those are pricey. 

So I would start by putting other loads on the outlets those devices are plugged into.  A 1500W heater should give a good test.   If the AFCI trips under those conditions, then it is a wiring problem and I would focus (in this priority)


multi-wire branch circuits first, just because it's easy to cross off the list. 
crossed neutrals, as discussed, which means mapping the circuit, opening up every box in the circuit. 
any loose wire anywhere in the circuit, which would cause genuine arc faults. - converting backstab connections to either screw or screw-and-clamp, as backstabs are not as reliable, and sometimes cause genuine arc faults. 


"re-splicing the same wire 100 times" won't do it. Re-splicing every wire in the circuit once is a better use of your time. 

Otherwise the appliance may be generating an arc fault internally. Test that by wiring an AFCI direct to a single receptacle only, and plugging the appliance direct into that, and seeing if it trips.  

P.S. are you actually landing the circuit neutral on the AFCI?  Or is it still going to the panel's neutral bar?