Most probably CPANTS databases are being regenerated from scratch due to major changes in Kwalitee metrics or updates of relevant modules/perl. Usually this maintenance takes about a day or two, and some of the information may be old or missing tentatively. Sorry for the inconvenience.
No Core Issues.
If you are using Build.PL define the {requires}{perl} = VERSION field. If you are using MakeMaker (Makefile.PL) you should upgrade ExtUtils::MakeMaker to 6.48 and use MIN_PERL_VERSION parameter. Perl::MinimumVersion can help you determine which version of Perl your module needs.
Add 'use warnings' (or its equivalents) to all modules, or convince us that your favorite module is well-known enough and people can easily see the modules warn when something bad happens.
Error: Physics::Unit, Physics::Unit::Scalar
This is not a critical issue. Currently mainly informative for the CPANTS authors. It might be removed later.