Hi @Andrea27993530aiie,
Thanks for the clarification. Since docking works on the Mac Studio where previous Illustrator preferences were imported, I recommend importing the same Illustrator preferences on the Mac mini as well. You can do this by copying the Illustrator preferences folder from the working Mac Studio user library to the corresponding location on the Mac mini while Illustrator is closed, then relaunch Illustrator and check the panel docking behavior. For reference on location: How to set preferences in Illustrator
Please let me know how it goes after trying this.
Abhishek
Well thanks for all the answers, I have fixed the problem in a simply way... I uninstalled the program by deleting all the preferences and then reinstalled it, now everything works fine