Metronome bug

I often use a double time metronome, like, project tempo at 70bpm but the metronome at 140.
So I go to the metronome options and set it to 1/8 instead of 1/4.

Now my problem is when I cycle,say to a bar…initial start, metronome behave normal, 1 high pitch then 7 down pitches… ok fine, then it cycles back to start and now i got only 1 high pitch, a blank/muted one and then 6 normal down pitches.
It’s really weird that every cycles it mutes the second beep…but if I put cycle mode off and play through the project there are every beeps in 1/8.