Beersmith out of the box is not a magic wand that you wave to get what you want. You
must create an accurate equipment profile or your results will
never match the estimates. You can create this profile from scratch or you can modify a profile that comes with the software. I have attached links to two tutorials that will walk you through the process. I've used both with good results.
Two things about the profiles that come with Beersmith. 1) They have been created and submitted by Beersmith users. 2) Brad Smith even recommends you only use these as a starting point in making your own profile. Why? Because everyone's process is different. Those users who submitted the profiles are trusted users who know what they are doing BUT their process, even using the same equipment, is different than yours and mine.
Beersmith can be extremely accurate if you take the time to work on the profiles. I'm in the process of fine tuning a new one myself for a new Anvil Foundry 10.5. I am three brews into it and still making small tweaks. I expect the next batch to be spot on. The point being however is that it takes effort on your part to make it work. Instead of attempting to "
prove beer smith wrong" you should be taking the steps necessary to make it work for you.
This is the first tutorial I used and it still works well...
https://youtu.be/QmW7pwQP5mQThis one came later and I like it better for including the volume calculator...
https://youtu.be/HwEbjOt8OR8