The $container_title variable seems to no longer be exposed in JSON UI. No amount of string manipulation or matching will work as of 1.20.30 i.e.
($container_title = 'Title123')
or
($container_title + 'ABC')
or
(($container_title - 'custom_string') = $container_title)
Steps to Reproduce:
Apply the "Chest UI Example" pack attached.
Name a chest "blue>Chest title here"
Results:
The chest no longer changes styles, whereas on MC 1.20.15.1 and lower, the chest appears blue as intended.
Screenshots/Videos attached:
Version 1.20.15.1:
[media]Version 1.20.30.2:
[media]Notes:
There's a very high likelihood this issue is a result of whatever was done to fix MCPE-161134
Attachments
Comments 4

As pointed out by ofunny on the GeyserMC Discord, all you have to do is to create a local copy of $container_title.
Quote ofunny:
To solve this issue, just simply create a local copy of the variable, as it should be done, if the variable is being used to do comparison or any other manipulation of it.
"$fart": "$container_title",
"$ofunnymenu": "(('%.2s' * $fart) = '§')",
As pointed out by ofunny on the GeyserMC Discord, all you have to do is to create a local copy of $container_title.
Quote ofunny:
To solve this issue, just simply create a local copy of the variable, as it should be done, if the variable is being used to do comparison or any other manipulation of it.
"$fart": "$container_title",
"$ofunnymenu": "(('%.2s' * $fart) = '§')",
Thank you for your report!
After consideration, the issue is being closed as Working as Intended.
Please note, that mechanics of the game may change between updates.
Things such as graphics, sounds, world creation, biomes, redstone, villagers, and animals may not work the same in current versions.
Full Version History – Snapshot Version History – Feature Requests and Suggestions
Quick Links:
📓 Bug Tracker Guidelines – 💬 Community Support – 📧 Mojang Support (Technical Issues) – 📧 Microsoft Support (Account Issues)
📓 Project Summary – ✍️ Feedback and Suggestions – 📖 Game Wiki