Earphone jack not staying seated; head/earphones drop out via software

I’ve had this LG Optimus Zone 3 for 23 months before having this problem. The earbud or headphone jack operates normally, it “clicks” when you insert it into the headphone jack, and the icon pops up correctly, etc. But 1-3 seconds after you release the earbud jack, even though it is still in the jack itself, the icon changes from headphones to half-headphones and disappears, and you lose the earbuds as if you physically removed them. I have removed the protective additional rubber cover, and this has not fixed the problem.

Pressing hard side-to-side or up-or-down against the earbud jack while it is inside the headphone jack keeps the earbuds connected, but as soon as you release the pressure, the earbuds drop out again. The earbud jack is not falling out, I have attempted to clean the headphone jack with both Q-tips and a steel safety pin, with no results. But the earbud jack refuses to remain connected after being plugged in.

Is there a cleaning method I’m not familiar with, or is this going to be a “black box” replacement of the headphone jack? (The power connector also likes to fall out randomly.)