DPD Labels Not Scanning- Prime Orders

We have two business accounts with DPD.
Our other account we print DPD labels from their own portal, using a smaller label.
Our Amazon labels we purchase inside of Amazon Buy Shipping on a 6 x 4 and they have been fine for years up until now.
My DPD driver is ranting at me saying DPD labels for Amazon parcels arent scanning and he will no longer collect as its not paid for the ones that do not scan. Our driver said its a change to the DPD system but DPD are saying theres been no change.
DPD are saying I need to speak to Amazon to change the format size, however Amazon only give me 6 x 4 option or 8.5 x 11.
Is anyone else having this issue and figured out whats helped?
It seems they are passing me between the two and I can’t get an answer. But my Prime orders need to be collected!