Tons of formatting issues on actual device, perfect on simulator

I am making my 1st app and finally tried it on my own device after running it for months on the simulator. I was assuming they would look the same - what a wake up call. Font sizes don't match, things are layered wrong, visually it's a mess. functionally it is fine. How does one correct for these issues for different iOS versions without counting on simulators??

Tons of formatting issues on actual device, perfect on simulator
 
 
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