Firstly, apologies if this is something I have misunderstood, but I'm fairly sure this wasn't an issue before the UI upgrade. I know the below is written in prose, but it felt like the only way to clearly explain the issue.

The issue I am experiencing is with regards to world subscribers not being able to view articles. Here is some context: I have a world set as Private. This world is being used for a D&D (5e) campaign, and has the campaign elements integrated with it. The Campaign has an associated subscriber group, with which my players are members. The world has many articles. Some are set to private. Others have been private, but as my players unlock the information/discover new places, I toggle the article(s) to Public.

Recently, I added a new article and set it as Public, but my players were complaining that they weren't able to access it - despite it being visible under the relevant section on the world's contents page. If they follow that link through the world homepage, they end up on the Multipass? screen.

Now, It is possible that I have misunderstood the permissions system (in which case my apologies again for wasting your time!) however it seems odd that a Public article would not be accessible by anyone who can already view the world... Additionally, having to manually add a subscriber group to every article in addition to making it Public so it appears in the contents list seems inefficient...
Moreover, when an article is set to Public, this hides the part of the UI that both displays and lets you alter the list of subscriber groups for the article. This leads my to the next part of my issue.

If the above behaviour I have described is in fact intended, it then would suggest that the hiding of subscriber groups when setting an article to Public is in fact a bug in and of itself. I was able to test though two of my players (each using a different phone OS - iOS and Android) that an article that remains private but has the campaign subscriber group attached allows them to view the article. Flipping the toggle to Public hides this subscriber group edit option, but my players remain able to see the article. Returning the article to Private brings back the subscriber groups option, and demonstrates the campaign subscriber group is still attached to the article. Removing the subscriber group blocks their access again.

So to my mind, either there is a bug with article permissions, the UI isn't display the full set of permissions (i.e. Public + subscriber groups that are also in effect) or the permissions system just feels unintuitive (to me!!).

An additional comment:
I am unable to really test everything I have described above! As my account is the owner of the world, everything is visible to me. I will probably submit the following as a feature request, but I thought it bore mentioning here as it is contextually relevant!
It would be nice to be able to toggle the permissions level with which I view my own world. The only way I think it is possible to do this (that I can find) is to create a totally separate 'dummy' World Anvil account and attach it to my world. I could then use this to test what I can and can't see. However this would take up one of the precious few subscriber slots on my world. As I have a good number of players (not all are yet set up on World Anvil - I'm desperately trying to persuade them) this doesn't really work for me - I expect I could max out the 10 subscriber slots (for my Master tier subscription) with players. I appreciate that there are more pressing matters given the list of bugs concerning the new UI update, but this has been a thorn in my side for a while now and this isn't the first time that I didn't know my players didn't have access to articles until weeks later! I really like World Anvil and I've been trying to persuade more of my players to make use of it, but its hard to convince them when they can't access the content.

Once again, if this turns out to be my misunderstanding then my deepest apologies! I'm extremely busy with session prep and I'm submitting this report very late in the day, so its possible this isn't the clearest explanation - sorry!

See above (sorry its a bit long winded, but it requires a minimum of 2 accounts).