Inconsistency in crust vs. inside...maybe an altitude thing?

I am a pretty new baker so still figuring out many, many things! My most recent challenge is that many things I try are baking noticeably faster on the outside than on the inside, so I end up with burnt crusts and raw dough inside. So far I have run into this while trying to do sandwich bread, english muffin bread and soda bread.

I initially guessed incorrect oven temp, but after getting an oven thermometer and several tests, it has been within 5-10 degrees of the temp setting each time.

I live at about 5300 feet so altitude issues was my next guess? I try my best to adjust recipes as needed for altitude but maybe I am missing something?

Thoughts or other suggestions?

Thanks!