I’m having a lot of problems with my charging. Sometimes I connect the charging cable, the “charging” light turns on, but the device doesn’t charge (or charges extremely slowly, such as 1-2% overnight). Just disconnecting the cable and reconnecting fixes the issue. I think the charge socket is getting loose.
Are there apps where I can monitor the battery current? This would allow me to see when I have issues (also to do quality check on the various cables I have). Something onn F-Droid would be preferred.
Assuming you have a recent device which supports USB-PD, you can get USB-C cables that have a small display built in that tells you how much power the device is currently pulling, in watts. It won’t help you validate your other cables, but will help you determine if the problem is really in the phone.
But your problem may be even easier to fix. Sometimes schmutz gets stuck in your USB-C port and prevents the cables from getting fully plugged in, or prevents the clips from engaging to keep the cable secure. Get a (plastic!) toothpick and use that to root around the port a bit, then use a can of air to clean it out.