"Swing" bug with measure rests

Let's say we have a Jazz duet of Piano and Trumpet, and that there is a Piano solo introduction in the first 4 bars.

1 - I wrote "Swing" for the playback: "Swing" will be written at the first measure on both Piano and Trumpet parts;
2 - I pressed "m" in order to display a multi-measure rest in the Trumpet part;
3 - I decided to hide "Swing" with "Cmd + V" in both parts - it'll be hidden but it won't work for all of the not-playing instruments.

In fact, for some reason, when doing things in this order, "Swing" will stick in the exported PDF. Also, when you save, close, and re-open the file, the modification of point 3 will be withdrawn: "Swing" will still be there as you didn't do anything in any of the instruments at rest (this also applies if I had a Clarinet, Trombone...).

Note that I hide "Swing" after pressing "m", so it may not be bugged if you hide it when the bars are not grouped... but that's a bug. In fact, It seems that there are two separate files, one with the grouped measure rests, and another one, as this could be solved by hiding it - "Swing" - when the multi-measure is not shown.

It's kind of a mess and may apply to all kinds of information added in the rest bars.

Thanks