Why Won T My Av Receiver Recognise This Usb Flash Drive

I’ve been using Kingston DT101G2/64GB with my Pioneer AV receiver and I like the price and capacity so I bought another Kingston DT101G2/64GB. However, after formatting the USB flash drive on my Windows 7 PC and moving music files (and testing whether the files can be played with VLC), the Pioneer refused to recognise the USB flash memory.

I checked both Kingston and found both are now exFAT with 128 allocation unit size and everything including driver version is the same.

Can you please help me solve this mystery? Many thanks.