Exact same problem for me too. I asked in the chat if “anyone had lost their [Karmic Retribution] post getting the [Cold Resistance] buff” and someone else said they had the same issue.
I left Bitterfrost to Ember Bay and still had my karma buff there and returned the Bitterfrost version was still missing. I haven’t received any karma bottles since but its difficult to say whether it was bad luck or related.