My original problem was I had to edit(remix, change length) music in an external editor(Reaper) because in Fairlight I can't set bpm as timecode, but this cause another problem, resolve lock the file during its running, so the Reaper can't overwrite the old music file with the new one, so I had to import over and over again but during the import I lost the Resolve markers.
After some hours I figured out a relative good workaround: I use a compound clip, putting music file into and on the enclosing timeline I can set markers on this embedded compound clip so I can change the music files without losing markers
The better solution would be if the "replace selected clip" function didn't remove the markers!
Bye