Before you read further, listen, first off I know it’s not a head gasket, it’s been checked (not by me, a shop did it real quick for free) nobody seems to listen they just jump to head gasket (which it isn’t)
my car has a brand new radiator I accidentally over filled reservoir, was leaking around reservoir and spraying it on resonator (2003 Civic Lx Non VTEC) the shop I went to clearly stated it’s not purging coolant, it would have actually broken the cap on your reservoir. But since I emptied and cleaned the reservoir and properly filled it up where it needs to I haven’t noticed the issue. Could it have been reservoir?