QC 3.0 power bank stopped working after update on X20

A few months ago (end of last year perhaps) there was an update to the X20. After that, my quick charge 3.0 power bank stopped working with it. When I plug it in there is a brief display of charging, then goes off.

It doesn't matter if the power bank is fully charged or not, whether the phone has lots or little power remaining, or even off. It simply does not charge. It worked fine until the update, and the power bank isn't broken, as my other phones and devices continue to charge without problem (including phones and tablets on various android versions). The X20 also charges well with another power bank, some cheap thing bought online that isn't QC.

Does anyone have any ideas? There's nothing in the battery settings that is relevant, and settings are similar to what my other devices show. I really want to get this working again, as the power bank is big and was expensive.

Thank you in advance for any help.