Ok.. good update. After Fidesmo support informed me that they never actually tested Klarna account tokenization to a P71 JCOP 4 chip (Apex) only their new JCOP 4.5 chips, I tested both. I found a tokenization error which blocked access to PPSE payment processing options on Apex chips for Klarna accounts. Sent full report to Fidesmo support. Confirmed Klarna tokenization is working for US accounts on JCOP 4.5 chips.
Hopefully they will have a fix in soon and anyone with a Klarna account can re-tokenize to their Apex Ring conversion and it should work.