Question [Q] Charging mystery. PCs no but detects. Wall yes. Cables, ports, pcs, oh my!

I'm asking for a solution to get my phone to charge via PC when phone is on. I've been troubleshooting this for days. I have a Sony Zperia Z Ultra, so the battery cannot be removed. This is what I've determined:

Phone charges when OFF and connected to PC.
Phone charges when plugged into wall.
Phone shows USB debugging is active when plugged into PC.
-If USB debugging is disabled, phone will not show any indication of being plugged in.

Phone's battery status is "not charging" when plugged into PC.

PC shows phone in device manager.
-Device manager shows yellow triangle next to phone name regardless of the PC I use (all of which previously worked fine).
-Have tried uninstalling and reinstalling drivers but all PC refuse to recognize the Sony drivers for some reason. I'm also at a loss on how to get the drivers installed properly, or how they got messed up in the first place. This happens for all PCs however. But regardless of drivers, the phone should still be able to charge once plugged in. It does not.
-If USB debugging is disabled, phone will not show up in device manager.

PC makes USB connection sound/notification when plugged in.
-If USB debugging is disabled, PC will make no sound/notification when plugged in.

PC will NOT show phone in Explorer (SD Card does not show up, nor can you navigate phone directories).

Have tried 3 different computers and laptops.
Have tried 4 different USB cables, both third-party and branded.
Have uninstalled recently installed programs (from both PC and phone).
Have tried resetting, rebooting, and hard rebooting phone.
Have tried cleaning the mini-USB port on the phone, it's nice and shiny.

Have used phone for about 6 months, problem just started happening about 2 days ago for no apparent reason, no changes were made on PCs (tried several) and especially not the phone itself.

Any ideas? I can only assume it's a phone issue from using above factors to narrow it down, however which phone factor should I focus on?