Script Not Running as Administrator on Single Account

Let me start by commenting that I have little experience with GIT and no experience at all with whatever "spicetify" is.

This explains how UAC works.

https://learn.microsoft.com/en-us/windows/security/application-security/application-control/user-account-control/how-it-works

In short, even if you are a member of the administrators group, you don't get full administrator access unless you go through the UAC elevation prompts. That is how Windows works by default. If you changed the UAC settings and disabled that, then that's another issue.

If I search for Powershell I see 2 options.

If I select "Run as Administrator" I get a UAC prompt and have to click on OK to continue. When Powershell opens I then see that the window title says "Administrator: Windows Powershell".

If I click on "Open", I do not get any prompt and the window opens up. The title just says "Windows Powershell".

You can see the difference in the images that I posted.

What I did there was to download the Install.ps1 script and take a look at what it was doing. I found the Test-Admin function where the "Checking if the script is not being run..." message comes from. I ran just that function in the 2 windows.

It appears that the script has a builtin vulnerability test where it wants to insure that users run it from a non-elevated PS prompt. That's probably intended to stop other bad actors on the internet from uploading malware scripts to GIT and then infecting users like you who run the script.

Your best option would be to select "Open" to launch Powershell.