We just covered transitiivi vs intransitiivi in my Finnish class this week.
Is there much of a difference of meaning between using a transitive verb in passive voice compared to using an intransitive verb? It seems to be mostly the same in my foreigner’s mind.
I’ll preface by saying I’m not a native speaker, I just finished the fourth module of kototumiskoulutus.
I believe the difference is object. Intransitive actions don’t have objects but passive does have an unknown or unsaid object.
After looking this up quick I found exactly what you might be looking for.
https://uusikielemme.fi/finnish-grammar/verbs/types-of-verbs/transitivity-and-intransitivity-different-derivation-types
Section 4 covers the intransitive versus passive. I believe 4.2 especially shows where the confusion may be.