Great Shanul. If the ActivityStarter browser cannot render your website, then you will find App Inventor impossible to replicate it. Your options are probably limited to the professional Android Studio, B4A and Delphi Community Edition (or a few others) that might allow you to create a functional browser for an Android app.
... that is a correct statement, unfortunately for you.
If the ActivityStarter browser does not render your Web page with all its bells and whistles, you are probably out of luck using App Inventor. Don't give up; someone else might have another opinion, and post something that will help.
C+, yeah, been there done that and a pile of other languages. You may have to learn Java if you are going to fulfill your Android dreams. Good luck!
By the way, Delphi has a compiler that will render on Android code that works on Windows. Delphi is expensive; however they provide a 'free' compiler that is cross platform that might be of interest to you https://www.google.com/search?q=delphi+community+edition&rlz=1C1CHBF_enUS887US887&oq=delphi+community+edition&aqs=chrome..69i57.9391j0j7&sourceid=chrome&ie=UTF-8 This might be a way forward.
It is free until your app starts making significant revenue.