There may be something else going on too preventing the folder selection from working. Maybe the folder permission won’t allow the plugin to access it.
However, it is still normal for the folder to show empty when double clicking on it. The plugin folder select window is different than the file/open window in Photoshop. The way Adobe designed the plugins folder select dialog window won’t show images inside of it when double clicking on the folder. It always shows empty. That was the way Adobe designed it, not me. There is nothing I can do to change that window behaviour.
Anyway, let’s just do a screen share. Please install the remote desktop app for Google Chrome. It is a free extension for Chrome. Then you can email me an access code to log into your computer with you.
The access code is only active for 5 minutes. So let me know an exact time you want to do this so I can be ready to check the email for the code at that exact time.