>> Finally I get to know why my mortgage was declined :)
My first attempt at one was declined due to "problems with my credit report" or some such. I happened to be working at a place where they did credit checks on customers, so I asked someone to pull my credit report. They had all my stuff, but had mixed in a bunch of information from someone else with the same name - different age, there were loans on there from when I was 3. I called the reporting company to complain and they kept getting caught up in "how did you get your report?" as if I had done something wrong in just having access to their incorrect information. Perhaps having someone pull the info instead of the "consumer" getting it through proper channels was against some rule - this was 1995. I think the same is often true today, companies want to collect data on you but don't really want you to know what they've got or how they use it.
This is exactly why you are legally entitled to receive a copy of your credit report every year. You can challenge anything on it, and have incorrect information removed.
If you are one of the people just finding out about this today, and you Google "free credit report", you come up with a loooot of bad, scammy links. This is how you get your legally-mandated, really free, annual credit report, starting from an ftc.gov address so you know it's really the right one.
To be fair, the credit score (VantageScore 3) you provide is not the credit score (FICO) most people are interested in, and that is used for most credit decisions.