Take a look at https://metacpan.org/dist/Lexical-Var/changes. There were a huge number of bug fixes in Lexical::Var released on Mar 24, including several mentions of thread safety. If Redhat's packaging for 5.36 ecosystem didn't include that new version, that would explain why.

BTW, any time you change perl interpreter versions, you *should* see a massive number of packages upgraded or downgraded because every perl module needs re-installed for that version of perl.

(technically the pure-perl modules don't, but their Makefiles might behave differently depending on what other module versions are available, so even pure-perl ones ought to be re-installed generally)