Spacebar doesn't activate the pan (hand) tool in Illustrator 23.1.1/Photoshop 20.0.6 CC2019?

Some other piece of software is probably stealing the shortcut. Try looking at the OS ones; especially since you moved on to OSX15. My advice when using Adobe products is never be a first adopter.

Hi Jannes,

Sorry to hear about the trouble you are facing with Illustrator Hand Tool. I would request that if you can share a few more details like: 

1. When did this start happening? Are there any recent changes made to your system? For example, any antivirus, system updates or web extensions installed recently. 
   
2. When you re-installed the software, did you keep the old preference while installing? If yes please try resetting the Preferences manually following below steps:

• Close all Adobe applications. 
• Go to locations 
• ~/Library/Caches 
• ~/Library/Application Support/Adobe 
• ~/Library/Preferences 
• Rename  Adobe Illustrator, com.adobe.illustrator and Adobe Illustrator 23 Settings folders to   Adobe Illustrator.old, com.adobe.illustrator.old and Adobe Illustrator 23 Settings.old 
• Launch Illustrator from the Creative Cloud. 

Disclaimer: Please note that resetting preferences will remove all the custom settings and Illustrator will launch with default settings. This way all your old settings will be saved in .old folders and Illustrator will recreate new folders with default settings.  

Do let us know if you need further assistance.

Regards

Rishabh