In the latest strawberry perl 5.24.1, cpanm --self-upgrade does not work. Using cpanm App::cpanminus does work, providing a work around.

C:\WINDOWS\system32>cpanm --self-upgrade
Can't find Unicode property definition "e" in regex; marked by <-- HER
+E in m/^C:
\STRAWB~1\pe <-- HERE rl\site\bin/ at C:\Strawberry\perl\bin/cpanm lin
+e 33.
[download]

You will need to also delete the cpanm and cpanm.bat from C:\Strawberry\perl\bin, if your system is setup properly cpanm will use site\bin.

Anyways, here's hoping this helps someone else.
--dave