I don't use the debugger (except in exercises like this) so it's more trial and error than knowledge for me. Anyway, I found the issue actually revolves around whether p or print is used.

$ perl -C -de1
...
  DB<1> print "\x{263A}"
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  DB<2> p "\x{263A}"
Wide character ...
...
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My guesswork here was based on a long-standing alias of mine:

$ alias perlu
alias perlu='perl -Mstrict -Mwarnings -Mautodie=:all -Mutf8 -C -E'
[download]

For example:

$ perlu 'say for $], "\x{263A}", "\x{ 263A }"'
5.036000
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Update (checking for false positives):

$ perl -de1
...
  DB<1> print "\x{263A}"
Wide character ...
...
☺

$ alias perle
alias perle='perl -Mstrict -Mwarnings -Mautodie=:all -MCarp::Always -E
+'
[download]

$ perle 'say for $], "\x{263A}", "\x{ 263A }"'
5.036000
Wide character in say at -e line 1.
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Wide character in say at -e line 1.
☺