I ve been having this since ages now but its really hard to open a ticket nowdays.
Practically my alts (same addons and Blizzard interface) with my main have the party chat not displaying any messages at all.
I have no idea what the error could be. I have the latest updates for my addons and i crossed out addons since my main is using exactly the same ones without an issue.
Party chat is enabled and i have tried resetchat, relog, reload, disabling/enabling chat without success.
Just because your addons are all updated and working on some characters and not others, doesn’t mean it isn’t an addon - sometimes addons do some weird stuff
Try disabling ALL your addons and see if the problem persists. Make sure to disable them, exit the game completely and then re-start. If the chat works fine then, then you know it’s an addon issue. I’d then recommend getting bugsack/buggrabber addons (they’re small and work together) and see if they show any errors (you’ll get a warning sound “Fatility” and the little “sack” icon will turn from green to red). Go through the process of disabling the addons that are erroring, initially, and then it’s just a matter of trial and error. Sometimes the addon that breaks isn’t related to your issue, but it causes downstream errors in other addons.
If you disable all your addons and the problem still persists, it could be a corrupt file somewhere - you could try a game repair from the launcher?