The cast bar option is enabled for all my frames including "Party", "Target", "Pet" and "Raid", however the only cast bar that appears is for the "Player" frame.

Could you help me to enable it to be able to see the cast bars for my targets and party members.

Noticed this as well on sod, party frames aren't getting castbars.

Looks like this might be an issue with LibClassicCasterino, if i disable the code that loads the functions from LibClassicCasterino party cast bars start working

So pretty interesting....

Partied up with 1 other person and had them cast hearthstone

With LCC enabled
No party cast bar
Target castbar appears
Have them hit escape
Nothing changes with party frame
Target cast bar keeps going for the full duration

Challenge them to a duel
With LCC enabled
Party castbar appears
Target castbar appears
Have them hit escape
Nothing changes with party frame
Party castbar stops
Target castbar stops

With LCC disabled
Party castbar appears
Target castbar appears
Have them hit escape
Nothing changes with party frame
Party castbar stops
Target castbar stops

So it seems like there is an issue with LCC and non-hostile members

Should be fixed with next release.