do you have the right flint length ? if its to long it can catch the frizzen .
next i would check for free movement by working the frizzen back and forth . it should move freely . Fouling can build up in the frizzen bridle and cause the frizzen to hang
If everything clears and is free I would then go to the small toe cam on the bottom of the frizzen . This is the small section that rights along the frizzen spring . , use alittle 3 in 1 oil or graphite where the slides across the spring