A question about MyHeritage

[LaSentinelle]

So, recently I uploaded my DNA sample onto MyHeritage and got my results. My genetic makeup is pretty much what I expected (89% East European, 8% Baltic, 1.5% Balkan and 1.5% Inuit for some reason, but that's fine) however there's a feature I'm not entirely sure about. So, when you're looking through your Ethnicity Estimates tab, there's a thing called 'Genetic Groups'. Apparently, these are populational clusters which are of the same or similar DNA makeup (correct me if I'm wrong). So, in that tab if you click on any of your genetic groups there's an option to view this genetic group's 'Timeline'. And here's when the fun starts.
In the 'East European' group I have 5 Genetic Groups, 3 medium confidence groups and 2 low confidence groups. When I started looking through each of those groups' Timelines and scrolled all the way back to 1600s and 1700s, almost none of my Genetic Groups had ancestry that came from Russia. All of it was either Poland, Norway, Germany, England, or even the United States (???). I've attached a couple of examples.
Additionally, most of my DNA matches come from the US, Finland, Germany and Sweden for some reason despite my not having any recent family there (tbf all of those results say that those matches are my parents' 3rd of 4th cousins or something of that sort. So that's not my immediate family, but someone who is related to me).
So my question is, what does all that mean and how could I interpret these results and have a better understanding of where I come from? I mean, if I was 100% Russian wouldn't it just say that straight away and not match me with anyone from the US, Germany, Finland or Sweden and not show that I, apparently, have some ancestry from Norway, Germany and England?
I've also posted a lot of G25 calculator results if you're interested to see my results. I can also run whatever G25 calculator you want if that would help you interpret my results.
Thanks!

[Petalpusher]

Most Euro will match with Americans despite having no known family members from there. That's because other distant cousins you never heard about in your family might have emigrated establishing a continuous link. Let's say one of your distant Russian relative marry a Norwegian or an Italian in the US, their offsprings will now also be linked to you through their Russian side, and you with their Norwegian and Italian ancestors back in Europe too. That's perfectly normal. On 23andme the vast majority of my cousins are from the US too (and Canada) and i get other European nationalities through them as well. In some cases it can be recent or historical migrations within Europe but it should be more rare.

[PaulieVanZant]

Simple thing: afaik there hasnt been that much testing done in Russia, while I know for a fact that almost everyone and their grandma in Finnland has been tested already. There has also been subsistensialy more testing been done in America and Germany too. The American aspect has been explained by the person before and a lot of ethnic Germans (especially in the East) have a good portion of Slavic dna.