my phone had an issue with charging cables falling out. Turns out the port had compacted lint jammed in it. Turned the phone off and used a needle to clean it all out, phone retains cables now like the day it was new.
This. My phone reports "moisture detected" or oscillates between charging and not charging when there's crud inside the socket. I mechanically scrape it with the tip of a sharp pair of tweezers when it's lint, or I use the tweezers to swab with little pieces of paper towel soaked in isopropyl alcohol when it's something more nefarious.
I don't even bother turning my phone off, but it's rated as water resistant and so I am pretty confident that there aren't any voltages present when disconnected. Even on non-waterproof phones, though, any voltage persistently applied to pins on an external connector will result in corrosion over time, so it shouldn't be a problem to just mechanically scrape gently with a dry metal needle.
I don't even bother turning my phone off, but it's rated as water resistant and so I am pretty confident that there aren't any voltages present when disconnected. Even on non-waterproof phones, though, any voltage persistently applied to pins on an external connector will result in corrosion over time, so it shouldn't be a problem to just mechanically scrape gently with a dry metal needle.