I am in BIAB not Realband.
I have figured it out for myself now. Maybe the programmers missed something, but the time signature is not transferred from the chords to the audio editor. It does not appear in the chord view of the audio editor. But you can help it manually by opening the menu on the user bar line of the 2/4 bar with the right mouse button and setting the number of beats to 2. But then you have to move the start of the next 4/4 bar forward by half and set the beats to 4 again, so that it fits for the following bars. Very cumbersome, but it works. Would be nicer, of course, if the programmers would automate this. Also the missing display in the audio editor chord view would be very helpful.