BMW Nav VI not recognized using macOS Big Sur with BaseCamp v4.8.12.

I FOUND A CHEAP SOLUTION. I found an old USB-A hub in the back of a drawer, the cable is a male USB-A that plugs into the computer, the hub has three USB-A outputs. The hub is DATA ONLY, it does not charge attached devices. I plugged in the Nav V into one of the hub's ports, the hub cable into the Apple USB-A/C adaptor and plugged that into the M1 MacBook and eureka, the Nav V mounted.

No need to buy an expensive Satechi hub, any old tech basic USB-A hub with no power delivery should work.

I was hugely frustrated. Tried all of the suggestions offered and finally found this to work:

Powered on MacBook Air M1 13"

Powered on BMW Navigator VI

Plugged together a

    1) USB-C to USB-A Dongle to a

    2) USB 2.0 Mini HUB then the HUB to a

    3) USB-A to USB-Micro cable

Plugged in the above cable arrangement to EITHER of the two USB-C ports on the MacBook Air

Plugged in the USB-Micro cable end to the Navigator VI

The Nav VI went immediately into disk mode, the Garmin and SD card appeared on the Desktop. I started Garmin Express and it found the Navigator VI. I was able to install updates and maps perfectly. Basecamp saw the Navigator, 

All good!

Well done. I think the problem comes from TB3's power delivery, the spec allows for up to 100W charging, so directly connecting a satnav to a TB3 port puts the device in charge mode. We'll probably see more complaints with disk/charge mode devices as TB3 proliferates.

I am a long-time Garmin GPS user but a new M1 Mac person. Learning the new USB-C/TB interface is new and your comment was intriguing. I had not considered output POWER being a possible issue as I presumed that the connected device would only draw what it wanted. Also, the NAV-VI never even presented the "slave" screen but immediately went to the Home navigation "Where-To?" screen though showing that it was receiving external power as if it were in a cradle. I sort of thought it must be a comms speed or protocol issue and that the defined USB 2.0 HUB throttled the speed such that the NAV-VI was then happy with the then throttled speed/protocol. But ... what do I know. 

Oh: I just learned that one must be aware that there are Thunderbolt specific cables and though they look like ordinary USB-C cables, they will appear to "work" but must be used if one expects to enjoy TB speeds or other TB-specific capabilities. Also, the TB and USB-C ports LOOK the same but perform differently. The TB port can do everything a USB-C can do but not the reverse. 

So much to learn!

Glad it worked out for you.

Definitely not the first.  I have had this issue for over a year now and thought that I could wait it out.  However, I cannot update anything (or modify music or other content) since my MacBook doesn't recognize my NavVI.  Running Mac OS Monteray.  

I hesitate to suggest these things: make sure the computer's port is good, the cable is for data and good, try/change/eliminate a hub.  YOu can manipulate music and routes by putting the GPX or mp3 files directly on the micro SD pulled from the NAV. Managing maps might even be possible via the SD using MapInstall but it has been many years since I've done that (with old 276Cs and Zumo 550s). 

My Navigator V (made by Garmin) refused to mount on my M1 MacBook when connected directly using Apple's USBA/USBC adaptor.

Try getting hold of a USB 2.x hub, connect it to the M1 MacBook using a USBA/USBC adaptor, the other end to the satnav. This worked for me, my satnav mounts and I can use Basecamp etc as before. USB 2.x has 7.5 W power delivery whilst the M1's TB3 has 100 W, I think this is what makes a difference. 

I just ran into this problem. Garmin BMW Navigator V is not seen or recognized by the Macbook Pro M1 Max at all. 

However, you have just found the answer to where the problem lies! Thanks!

The MacBook transmits a high voltage at the output, which is recognized by the navigation as a charging process. And for this reason, the navigation switches to charging mode at the start and not to the mode of connecting to a computer.

My solution is:
Cheap adapter which is not able to transmit such a charging current. And everything works!

MacBook USB C thunderbolt -> universal adapter (HDMI / VGA / USB A/ USB C)  -> Cable USB A to USB Micro -> Navigator V

Which didn't work:

The solutions below simply passed a high charge current which was misdiagnosed by BMW Navigator V (Garmin motorcycle GPS).

MacBook USB C thunderbolt -> adapter male C to female A -> Cable USB A to USB Micro (checked many different cables)-> Navigator V

MacBook USB C thunderbolt -> a good quality adapter without its own power supply -> Cable USB A to USB Micro (checked many different cables)-> Navigator V

There are two options for solving this problem.
1. Garmin will make a new update, so you can manually switch from charging mode to computer connection mode ignoring the high charge current.

2. Apple creates a new USB protocol that will give you the option to select the device's connection mode when a new device is connected.

Anyway, until then we have fun with cables and dongles.

I just emphasize that on any of my Windows PCs there is no problem at all.;)

Best regards and thank you all for your attention.