Share for Review: public access no longer an option

Hi there

Until today, I never had an issue with Share for review (apart from "Could not update the artefact" errors every now and then. But now, I only get the Share for Review window with just the "Only invited people can comment" option - I used to be able to select the Piublic access option, but this is now gone. And when I do create a share link based on the only option available to me, I get a red error box saying "Error getting invited people". The link it created also does not work - saying "Something went wrong".

I have not changed a thing, and this only started happening today. 

I've tried:
* Reinstalling InDesign
* Clearing the cache and preferences
* Logging in and out of my CC desktop app.

Any help much appreciated.

System: Mac Studio M1 Ultra running Sonoma 14.6.1, 64 GB RAM