I've been having a problem with this for about a week now. I believe it's a bug or something wrong with the program but I don't know how to fix it. Whenever I move an item it creates this blue trail behind it.
We understand how frustrating it can be to encounter technical issues while working in Illustrator. Would you mind performing a clean reinstallation of the GPU drivers (Intel / NVIDIA / AMD) and setting the Graphics Preference to High-Performance for Illustrator (https://www.amd.com/en/support/kb/faq/gpu-110) if you are using a Windows computer and checking if it helps?
If you're on a Mac, kindly try manually resetting Illustrator's preferences and checking if it helps:
• 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 27 Settings folders to Adobe Illustrator.old, com.adobe.illustrator.old and Adobe Illustrator 27 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:
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.