external ssd disconnects on macbook pro 2023

You're welcome.

Please find guidance here:

Set sleep and wake settings for your Mac - Apple Support

"Prevent automatic sleeping..." can be found by clicking Apple menu () > System Settings > Displays (you may have to scroll down the sidebar) and then click "Advanced..." at the bottom of the Displays panel.

Also, in System Settings, find the Battery panel and click "Options...". You can set "Put hard disks to sleep when possible" to "Never"

Is this happening when you allow the computer to sleep?

This is a known problem. Sleep is not necessary with the new Apple silicon models. Disable the feature. You can just let the screen sleep after a time, but don't allow the laptop to sleep.

Another possibility is the the problem is is caused by a poor quality drive enclosure or cable.

Have you tried to use the the external ssd with a different cable?

Does the drive get its power from the computer, or from a wall plug?

Do you have other drives also connected to the Mac? If so, there is potential for RF interference from any of them that might cause a connection problem. Disconnect any other devices and/or create more space between devices to see if that helps.

You're welcome.

Happy to know you've got this sorted out. 👍🏽