Adventura 2 Plus, adding mosaic maps to microSD card

Dear TwoNav Community,

I recently bought the Adventura 2 Pro and am trying to get used to how it works.

I live in the UK and will likely use it mostly here so I also bought the full set of OS 1:25000 maps which I've used for walking in the UK before.

Looking at uploading the mosaic components I've managed to upload maps mosaic components to the GPS internal memory and I've managed to physically upload the map mosaic components to the SD card both directly via windows and using land (I bought a subscription) but I haven't been able to get the GPS to read the files on the SD card.

I've tried uploading the map directory into the SD card and mosaic componentes into that folder. Also tried replicating the directory structure on the internal memory but it still didn't recognise it.

Realistically I could just only load the moasic files for the area that I'm using the GPS in to the internal memory each time I use the device but it would be nice to be able to access those on the SD card. I can't work out what I'm doing wrong so any advice is greatly appreciated.

(Or if this infomration is somewhere on the twonav website a link would be great).

Thank you!