These findings challenge the common belief that sexual orientation is biologically predetermined and unchanging throughout life.
I really don't think this is true, nor does the study even imply this.
This study captures peoples perceptions and external communication about their own identity. This doesn't get anywhere close to deep enough to say "sexual orientation can change" - just that people can be wrong about how they communicate that identity.
That is fine, and is not surprising.
Yes, this is what I meant to express - understanding requires exploration. Externally, this can be viewed as "changes".