Changing your opinion when presented with evidence is a trait that defines your growth.
It's very easy for our opinions to be coloured by our biases. And it's impossible for human beings to not have biases. It's something that has been ingrained into our DNA and is useful when it comes to survival. But it really doesn't help us with growth in most of the modern world where our day-to-day existence isn't threatened.
So how does one overcome something like this?
By being aware that we all have biases and looking for evidence that goes against them. And by consciously acknowledging that our opinions were wrong and forming new ones. That is where growth lies, personally and professionally.
(This becomes difficult if you make your opinions as part of your identity but that's a topic for another day.)