one of my dragonflies not working with win tablet

I got two dragonflys 1.5
Lets call them DFA and DFB for clarity

DFA works automatically with everything with no trouble. This incl. my windows 10 tablets.
DFB refuses to work with my windows 10 tablets. There is no sound coming out. That’s the problem.
Both are found and automatically chosen as default speakers by win10 tablets.
DFB I installed firmware updates for in win10 tablet and it still doesnt work.
If I connect DFB to for example some old android phone, it works.
DFB has worked with my laptop and I am 99.999% sure it still does.
I Dont want to try cos its hard to reach its usb ports as it is inside of a ball of 40 cables.
unlike DFA, DFB didnt work with chrome in win10 laptop before i installed firmware updates.
Thats the only difference between these two dragonflys aside from win10 tablet issue.

Why arent’t my ZTE tablets w105 (tried all 5 of them) working with DFB?

dragonfly v1.5