Hello,
it is a know issue that particular USB Sticks does not work reliable under WCE/WEC! WCE/WEC has just one single driver which fulfill USB specification. Host PC has many drivers available, so OS may find one matches to your stick. We recommend to use only tested brands.
Assume your USB lines routed adequate for USB high speed: efus design guide. Else in some cases it may help to switch to full speed. Unfortunately this feature is not adjustable via Registry at the time and you need a new driver. Please come back then.
But I think we have the driver issue in your case, else more sticks would show problems.