Update to my previous post of 1/23 about my non-charging iPad Pro, about which the Genius Bar and Apple Tech support had no fix. After continuing to retry a number of different cables and charge cubes over several days with zero success, I concluded my iPad was dead, put it on a shelf, and ordered a new iPad from Amazon. A couple of days later, I realized I never tried using the power cable for my MacBook Pro, so I thought what have I got to lose. Plugged that in overnight and to my astonishment the iPad came alive and charged to 100%. I assumed this was a freaky thing and not a fix, so I experimented and drained the battery down by 5-10% to see if it would recharge. As I feared, no recharge from my MacBook charger after that one time. So I went back through my assortment of cables and charge cubes again. I found one, and only one, combination of cable and cube that was recognized, and it has been recharging my iPad for a week now. Will this last? Who knows, but I did cancel my order of a new iPad.
After reading the numerous posts about iPadPro charging issues in this and other forums, it's obvious that there is a charging defect in the iPad Pros or software, at least in older ones such as my 2018, that Apple refuses to acknowledge, and that is shameful company behavior. As a final note, whatever bug is in these iPads is a weird one. These posts have noted a multitude of different actions users (like me) have tried to revive their non-charging iPads that should, technically, make no difference in how the iPad responds, but some occasionally have worked for some users. Although mine is working now, I know that any day it could again refuse to charge for no discernible reason.