I had the same issue - everything set to MPH, but the live map would show KPH.
I did however notice that after a minute or so or watching the live tracker, the map would change itself to MPH instead.
But the next time you view it, it would be KPH again.
Yep, there's lots of little annoyances like this.
The computer software doesn't let you start/stop video with the spacebar. When you download a video clip and select a specific folder, it doesn't remember than for future clips and instead puts them in the default area.
The other day I found a section of the iOS app where some of the text was displayed in Korean, even though everything was set to English.
I wonder if some of this stuff occurs because they use things in kmph and don't fully test things out in other modes? Enough people have brought this up before that you'd think they'd fix it, but alas.
No, it never bothered me enough to report it.
I've since sold my DR900X Plus and got a DR970X Plus, but it's not connected to GPS yet (separate issue ongoing) so I'm unable to check on latest model. I had both until a couple of days ago.
I know BlackVue updated their apps and Windows/Apple viewer versions a few days ago - which included changing the map view (at least on Android anyway).
Are you still having the issue?
Is your issue on Cloud live view? Or is it when viewing recorded content on a PC/Apple.
If viewing on a PC/Apple - then everything may be set to MPH on your camera, but the PC software still set to MPH somewhere?