In my company we have been using Samsung Tab A6 tablets for months with a USB-C hub with PD and a barcode reader connected, all working smoothly. The tablet charges and the reader works, all at the same time.
We have purchased several Tab A7's and have been surprised that it does not work at all. With the hub connected the tablet does charge or receive data separately, but not at the same time.
We have tried 3 different USB-C hubs, all of them PD compatible. And 4 different chargers with PD 3.0 and QC 3.0: the standard one, one 30w and two 60w chargers, including an original Apple Macbook charger. No combination of them works. Any combination of them works on the Tab A6.
We have tried changing some settings on the tablet, such as disabling fast charging, but it still doesn't work.