RB751G-2HnD USB 2 Hub and GPS usb dongle

I would like to use the RB751G-2HnD with a USB hub and a GPS dongle + 3g modems, but cannot get the GPS dongle to work via the HUB.
I tried several hubs, and several dongles.
They all work directly on the USB port of the router, but not with a USB Hub in between.
I also tried with RouterOS 5.12, 5.13, 5.14, 5.15, 5.16, 5.17 and Version 6.0Beta2
The RB/SXT5HPnD shows exactly the same results.

Does anybody has something like that working?

Is somebody of Mikrotik able to answer this?

Support has recommended us to try with v4.17 (legacy), that is the only version working properly with USB. Mikrotik will be working in the problem (they are aware) once they release rOS v6.0

Any updates on that subject?

Regards