The issue is not tied to the 2/4 bar change.
We already got the same issue with Strings some months ago :

To enable Strings to mute during a rest bar, change the name of the chord of the rest bar :
/C… /C.d : The strings won't mute in bar#2
/C… /Cm.d / The strings will mute in bar#2.

I hope PG will output a fix about this annoying issue. Furthermore, using this workaround, we get a wrong chord sheet, because in the last example, we introdure an unwanted Cm just to mute the Strings.

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