Another problem is that UIListLayout no longer plays nicely with UISizeConstraint. It used to work fine, where if you have a Enum.UIFlexAlignment.Fill and a child element has a UISizeConstraint then that was seemlessly factored in.
Now it seems that the fill sizes are all calculated first, then the UISizeConstraint, so that the UISizeConstraint throws off all the sizes at the end of the frame.
Hi, thanks for reporting these issues! I had to modify the flex feature flags (configuration) in Studio last week, but I reverted those changes now.
Could you please check again to see if the shrinking and UISizeConstraint bugs are fixed? Thanks!
Yes that has fixed it.
Note that it would be good if you could publish a changelog or at least post something when you make changes. Otherwise I just load up studio one day and everything is random broken, with no idea what is going. on.
Note that it would be good if you could publish a changelog or at least post something when you make changes. Otherwise I just load up studio one day and everything is random broken, with no idea what is going. on.
That is actually a good idea! Not only that we would have better idea of what is going on when something changes (to better or worse) but we could also see the progress of the next few months of bug fixing!
Yes you are correct! We are currently testing flex layout in production. Please let us know if you see any new UI bugs!
However, we may need turn off flex layout on short notice if regressions are found, so please don’t rely on it being enabled! We will post an update when flex layout is unlikely to turn off.
I have my fingers crossed that it doesn’t need to get shut off, we’re shipping an update soon with a revamped game UI (now written in React) and it entirely relies on flex layouts. Having to rewrite chunks of the UI to not use flex layouts would be quite the hassle.
When will this feature be fully rolled out in the client? It’s been 7 months since this feature has been announced for Studio
Perhaps we should read the post above before asking such a question 
I think the user you replied to is asking for a specific date and not the way it will be announced
So it was working for like 2 days without the Beta feature enabled. (So you could use UIListLayout Flex with all clients)…now it’s back to only Beta…
What’s up with the random undocumented release/unrelease of features?
It wasn’t released at all. The fact that it worked on the client doesn’t meant the update was rolled out.
This is incorrect, it does not work in regular servers. When will it be out on all platforms? I did not realize it was a beta feature because it got enabled on its own. I really do not want to reposition all my UI again 
Sorry to hear this is making you reposition your UI!
We had to turn off flex layout on production because we found a few bugs in Studio and some games. I should be able to fix these soon and try to roll out again in the next few weeks!
Is it enabled in Studio still? Or does it require the beta feature being enabled?
Yes, flex layout is still available if you turn on the Studio beta feature!
Please tell me a date of when it will be officially re-enabled! It feels really counter intuitive for me to have to do all this work when this feature would’ve solved all my problems.
Is there a way to make the UI list layout wrap upwards instead of downwards when it wraps horizontally? No matter what I tried, it wouldn’t wrap upwards.
Oh yeah, it would be cool if it could take into account the alignment values (horizontal and vertical).