---
NODE:
  match: !!perl/regexp (?^ui:OK\ Server\ Connection\ 1\.001)

##</code><code>##

---
NODE:
  match: !!perl/regexp (?^u:(?^ui:OK\ Server\ Connection\ 1\.001))

##</code><code>##

---
NODE:
  match: !!perl/regexp (?^u:(?^u:(?^u:(?^u:(?^u:(?^u:(?^u:(?^u:(?^u:(?^u:(?^u:(?^u:(?^u:(?^u:(?^u:(?^u:(?^u:(?^u:(?^u:(?^u:(?^ui:OK\
    Server\ Connection\ 1\.001)))))))))))))))))))))

##</code><code>##

perl -MYAML::XS -E 'my $y=YAML::XS::Load(q{---\nNODE:\n  match: !!perl/regexp (?i-xsm:OK\ Server\ Connection\ 1\.001)}); for(1..20) { $y=Load(Dump($y)) }; say Dump($y)'