After installing High Sierra, preferences do not stick: PhotoShop images default to open in Preview
You probably have a couple of issues. First, I would repair the home folder permissions. Unfortunately, not everything you’re likely to use respects your home folder permissions, and they can get messed up. First rule of thumb is that everything in the hierarchy of the home folder should be owned by the user who owns the home folder. Go to Eclectic Light downloads and get RepairHomePermissions. Perform that, then reset your launch services database. Most Mac helper tools such as Onyx provide that, but here’s a command line for Terminal that goes to the heart of it:

/System/Library/Frameworks/CoreServices.framework/Versions/A/Frameworks/LaunchServices.framework/Versions/A/Support/lsregister -kill -r -domain local -domain system -domain user


You’ll get new app prompts for awhile, but it should help you get your launch services under control.

Unfortunately, we had to give up the default creator file properties in OS X some time ago, so unless the developer writes code of the sort I'm including below into the file saving process, your files open according to their name extension rather than according to what app created them. Part of your problem may be that you expect any file you create using a particular application to be opened in that application whenever you double-click that file. For that reason, you may want to enable viewing all name extensions in Finder (Finder>Preferences, then Advanced, “Show All Filename Extensions”) for awhile, until you get your defaults configured the way you want. Anyway, here’s a droplet source for AppleScript that will make Photoshop open individual files you drop on the AppleScript app you create from it. That is, it won’t change the app association for every file as you can if you use the check box in a file’s info window (which should work once your launch services are fixed). If you like, I’ll give you a longer one that provides the ability to choose between apps that you want to open the files by default.  I could also help you make a version to use in an Automator service that you could select from your contextual menu when you right-click a file or selection of files.

on open filelist
    repeat with theitem in filelist
        set filePath to theitem
        set target_file to POSIX path of filePath
        tell application "Finder" to set target_app to (get application file id "com.adobe.Photoshop" as text)
        tell application "System Events"
            set default application of file target_file to (target_app as alias)
        end tell
    end repeat
end open