ONGUI() Button Not working on IOS Build

I have an old unity 5 project that uses OnGUI().
Inside I have GUI.Button() that is called.
All of this works fine in the Editor, PC, PC Build, IOS Build (with new XCode 13)
When I update the project to Unity 2018.4, 2019, 2020 versions then It works in the Editor, but..
It does not work when I make an IOS build and run it on the device.

I even tried just making the first call GUI.Button() as a test in OnGUI(), but it does not trigger or hover.
The graphics in OnGUI() still draw properly and I still get MouseDown input.

I added a Canvas and Event system with a test Button and that works. Seems IMGU is not working for Input.

Any help on solving this? I don't know why it would not work in the latest versions of unity.
I can't upgrade the UI right now, was trying to get this updated version out now.

 

--RESOLVED--
To follow up on this in case anyone else runs into this.
It seems to work on Unity 2017.4, anything after that the OnGui() - GUI.Buttons don't seem to work on an IOS build.