[perl #130186] Match object inside .comb is weird (‘789’.comb(/ . {say $/} /))

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# New Ticket Created by  Aleks-Daniel Jakimenko-Aleksejev 
# Please include the string:  [perl #130186]
# in the subject line of all future correspondence about this issue. 
# <URL: https://rt.perl.org/Ticket/Display.html?id=130186 >


*Code:*
dd ‘789’.comb(/ . {say $/} <!> /)'

*Result:*
｢7｣
｢7｣
｢7｣
slip()

It may seem like it is stuck on ‘7’ and does not progress at all. However,
if we add parens around . we will get this:

*Code:*
dd ‘789’.comb(/ (.) {say $/} <!> /)

*Result:*
｢7｣
 0 => ｢7｣
｢8｣
 0 => ｢8｣
｢9｣
 0 => ｢9｣
slip()


I do not understand why the first snippet prints ｢7｣ three times.