External drive didn't show up as scratch disks after updated

Hi @Ka Long28504836tht2 is your external disk formatted to Mac OS specifications - AFPS Journaled? If the drive is formatted ExFat (Windows) the issue is since Big Sur/Monterey and now Ventura - Mac OS requires the proper formatting to be recognized. Use Disk Utility to reformat and it will show as a viable disk for scratch usage.

Hi @Ka Long28504836tht2 happy to try to help. When did you first notice this, what updates have you done recently?

Let's make sure we're in a default state and there are no stale settings somewhere: 

Restore your preferences using this manual method:  

https://helpx.adobe.com/photoshop/using/preferences.html#Manually  

Does it work correctly? 

If that doesn't solve it, you can quit Photoshop and put the Settings folder back. 

Thank you,

Cory