Issues with Show-InstallationRestartPrompt

I’ve got an SCCM application for an install process and I’m having it end with a 15min restart countdown. However, no matter what way I choose to run the toolkit I never get the Show-InstallationRestartPrompt.

-SCCM application is set for System or user, whether or not user is logged in. Allow Interaction by user is set.
-I have a Show-InstallationPrompt at the start of the install giving a message to the user that is showing up fine.
-If I run the script manually, I do not get a restart prompt. If I highlight just my Show-InstallationRestartPrompt and run it, it doesn’t work.
-If I just load the maintoolkit ps1 and run the command individually it will load.

I’ve not experienced this before and I’m a bit lost as to what could be causing the problem. Any feedback would be appreciated.

I am also facing the same issue with Show-InstallationRestartPrompt -Countdownseconds 600, which is not prompting any button to restart or postpone. Do you have any alternative option for me. Please advise