Question: Disappearing label

Hello, I wonder if someone could explain why, in the attached file, when I collapse the execution groups connected with the 3 equations the label (2) disappears but not the labels (1) or (3). Is there a workaround for this? Thank you View 2292_Label (2) disappears.mw on MapleNet or Download 2292_Label (2) disappears.mw
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