Two different micro-SDcards 128GB malfunctioning all the time

For my new digital audioplayer XDuoo X3 I bought a Sandisk Ultra 128GB micro-SD card.
But it seems unusable when trying to copy files to it.
Strangely enough the same problem occurred with the card of another (unknown) brand EVO. Thinking that it was a bad product I could give it back under warranty and replace it with the (much more expensive) Sandisk one.

The problem with both cards is that when files are being copied to it, it is only successful for the first 5-10 files. After that 'the target cannot be found' anymore, so copying stops.
At that moment a sound alert warns that the volume has been disconnected - its logo disappears from the 'computer volume overview page'. USB-unplugging the volume and reconnecting it brings the volume back in vision (with the usual sound alert). But after this a copy restart has the same results as before.

These problems always happen:
1. While syncing directly between my pc and the XDuoo with the SD card inside
2. While copying directly between my pc and TWO different card readers with the SD card inside

My conclusion is that neither the XDuoo nor the two card readers are the problem.
But if the SD-card itself causes the trouble, then this is strange:
1. If I attempt to use it directly from my music library MusicBee, that program reports that it cannot create new folders, because 'the volume is dirty' - whatever this may mean.
2. So every time I completely scan and fix the card, but never any problems are found: ready to use, says Windows.
3. Reformatting the card completely makes no difference.
4. How can it be the exact same case with two different SD-cards in three different devices?

Only 1 time around 4000 of 10.000 music files were copied, then it 'spontaneously' stopped with the error message mentioned. After this the maximum result always was 5-10 files being copied.

Could it be some sort of 'capacity' limitation?
Can Windows or one of my components perhaps not handle 128GB micro-SD cards???
A mystery so far.
MusicBee and XDuoo forums have not been able to come with suggestions.
Any help here?

UPDATE:
After I read somewhere on this forum another user reformatted his SD to NFTS I tried to do the same. The result is even worse: Windows keeps reporting that it can NOT format the volume... After lots of attempts it finally could do it 1x, but not to NFTS. Now again re-formatting is totally impossible.

Thanks for any support!
Wim

Give us more information of the hardware you have (computer and card reader).
The USB port that you're using is USB 3.1, 3.0 or 2.0?

There is a similar post here:
File transfers through USB 3.0 keep disconnecting

Test your cards. I've seen many fake drives.
Test it with H2testw to see if isnt fake. H2testw Download