As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LOUD FEEDBACK ON PA WHEN MAIN CABIN DOOR IS CLOSED -FOUND SAFETY MEGAPHONE IN ZONE B CONTACT WITH L1 DOOR CAUSE THE MEGAPHONE MAKE NOISE. R/R SAFETY MEGAPHONE IAW AMM 25-65-51. OPS CK GOOD A/C OK FOR SVC DRAWING NUMBER A321 NEO-EMER-EQUIP.