Europeans often follow the classical definition of socialism: non private ownership of means if production. Things like so socialist market economies without state regulation thereof, for example, are theoretically conceivable.
However, no European country is socialist in that sense. They have a lot of state involvement, or other public institutions, but they do have private property especially for means of production. That’s all there is to it, and calling Finland socialist seems rather inappropriate to Europeans. Indeed, to describe these different systems, other names are used, for example social democracy, or social market system etc.
For Americans, socialism is just the opposite of capitalism in every particular dimension, not just means of producing. So you can be more socialist in healthcare and so forth, even by having just more state control of things that are still privately owned.
Neither is wrong. It is a semantic misunderstanding.
Americans convey a lot of meaning by using single words. For example, just yelling socialism can now bring forth associations of all kinds, from Sweden to Stalin. Political discourse seems highly polysemic.
Europeans here are to some degree confused. It is not easy to keep up with the context of what socialism all means in the US, and how that meaning constantly shifts and gets new nuances.
But the vividness of it all is linguistically rather interesting.
Anyhow, no one is inherently wrong here.
I would however mention that we converse in English, on a US website. So there is that.