Thank you for the response Anshul.
So far it seems to happen in existing files and new files alike. When I go back to my Illustrator 2023 version, the gradients change color like they should.
I've attached a link to a screen recording showing the issue. In the recording I've created a new file, added a simple shape to my artboard, and then selected a default gradient. As you can see once I try to change the colors in the gradient panel, nothing happens. Thank you in advance for the asssistance.
https://shared-assets.adobe.com/link/86c39f48-2b1f-4211-464e-646726220681
Hello @MattG80,
Thanks for sharing the details. I was unable to replicate this behavior on my end. Would you mind trying to manually reset Illustrator's preferences and checking if it helps:
For macOS
• Close all Adobe applications.
• Go to the following locations
• ~/Library/Caches
• ~/Library/Application Support/Adobe
• ~/Library/Preferences
• Rename Adobe Illustrator, com.adobe.illustrator and Adobe Illustrator 28 Settings folders to Adobe Illustrator.old, com.adobe.illustrator.old and Adobe Illustrator 28 Settings.old
• Launch Illustrator from the Creative Cloud.
Note: Location starting with this "~" sign indicates the User Library, which is hidden. So, you need to copy & paste the exact path in spotlight search or from Finder Menu > Go > Go to Folder > Paste the location in the dialog box like this:

For Windows
- Close all Adobe applications.
- Go to Location C:\Users\%USERPROFILE%\AppData\Roaming\Adobe
- Rename Adobe Illustrator and Adobe Illustrator 28 Settings folders to Adobe Illustrator.old and Adobe Illustrator - 28 Settings.old
- Relaunch Illustrator from Creative Cloud
Disclaimer: Please note that renaming preferences folders will remove all the custom settings, and Illustrator will launch with default settings. You can also save a backup of the folders in case you want to. The location is mentioned above.
Looking forward to hearing from you.
Thanks,
Anubhav