Magic mouse secondary click won't work

Problem: My Magic Mouse (whatever it's called) secondary click will not work as right click. If I switch secondary click to Left click then it works and both clicks work (Left Click Secondary, Right Click Primary = works). But that is so weird to have secondary click as left click. When I make right click as secondary click then only left click will work & right click won't work at all Left Click Primary, Right Click Secondary = Doesn't work).

Solutions: All solutions I've tried have failed to work. I've gone to System Preferences>Mouse>Turned off Secondary click>Restart computer>Turn on secondary click. I've done this 20 times already.

I've done all updates on my computer. Running MacOS High Sierra version 10.13.6 as of today May 27, 2019. I have a iMac 21.5-inch, Late 2013 2.7GHz Intel Core i5.

I put in new batteries and restarted my mouse several times. To no avail will right click work as a secondary click. Again If I switch them then both left click & right click works but it's so odd having secondary click as left click. It's just not normal. Yes I could hold control & press left click to get secondary click to work. But I just don't understand why I can't get Secondary click to work as right click. And yes I've gone to the mouse menu, made sure Secondary click was checked & made sure it says "Click on Right Side". I know it's not the mouse itself cause if it was a hardware issue then when I switch them the right click wouldn't work at all. It has to be some software problem but I can not figure this out for the life of me and no one on the internet has yet to figure it out. I've watched 10 YouTube videos and they all give the same advice and say it'll fix it. Well it doesn't.