***It really depends wether the charger you're using is wireless or via USB.***
If you're using wireless charging, the adhesive on the charger that holds the magnetic coil vertically might if had the old degraded adhesive treatment which could move the wireless charger out of alignment for the tablet to read. And everytime you tap the charger, it moves the tablet a little meaning it wont be read easily.
On the other hand, if its the USB port you're using, this could be a problem with the tablet accepting the USB port. It could be a mixture of it not supplying the right current anymore or the USB port being doddgy and moving too.
I also dont see why you need that specific stand - there are tons of third-party charging stands out there....