I encountered something similar what seems like lifetimes ago - I was also using (pun intended) a combination of use base qw/foo/; (which is, we're told, equiv. to require foo; our @ISA = qw/foo/;) & require bar; my @ISA = qw/bar/;.

IIRC, most of the problems I encountered were resolved by changing use base qw/foo/; to use foo; our @ISA = qw/foo/; and also changing require... to use....

I reasoned, probably wildly inaccurately, that the change allowed perl compile-time access to the used class packages, hence it [perl] could resolve the method names earlier.

Just my 10 penn'orth