So it may not be debris in the port, given that you use a dust cover. I use a magnetic adapter so the post does not suffer from repeated physical stress.
However the ports contacts can be tarnished and they are fixed, so any physically loose issue can be down to the cable that has sprung contacts.
You can dismantle the actual bottom module for a better ‘clean’. You’ll see it’s pretty much a straight through connection which just passes the power to the core module which then decides how much to send to the battery.
You also may want to consider the contacts to the main board.