I did a test and it works as expected here.
If any settings I use, have no idea if they matter - just present them.
Preferences set to linear time, not following main ruler.
Looked through tracks for any musical and tricky part was that unless enough track height, timebase does not show - so missed some first.
Made a marker track, called videomarkers, and set timebase linear and put three markers at 20, 40 and 60 seconds.
Then moved some clips to to snap to these three markers, also having main ruler still at time linear.
Also made a marker track, called music marker, with timebase musical, switched temporarily main ruler to bars+beats to have snap working, and put markers on 5, 15 and 25 bars.
Switched main ruler back to linear.
Added tempotrack and activated it.
Changed tempo from start to 100 bpm - and all clips stayed at their time postion, as well as markers with timebase linear. Second marker musical moved as expected.
Activated second markertrack and jumped to second marker at 15 bars - and clicked in tempo track to add a node.
Changed tempo in inspector to 120 bpm.
And all three clips stayed in time postions as I hoped for, but musical markers moved, but not videomarkers.
You basically have to keep track if any musical timbased tracks that are locked, so they move with changes.
One way to have clips in place, would also be to lock them.
I tested insert time at some point, and locked tracks stay - which is good for video track itself.
Don’t know if I did anything unusual here - but that’s how expect to use things.
So those mentioning it is a problem for Cubase - what is that?