Could someone help me interpret this information?

[LaSentinelle]

Hi! I recently uploaded my raw DNA file onto "My true ancestry" and was flicking through the pages when I saw 'Your full Y-DNA breakdown'. This is what the results say. Somehow R1a and R1b are at the top and J (I assume they put both J1 and J2 in the same category) is only 2%, despite my having J2a1 paternal haplogroup. Does this mean that most of my ancestors had haplogroups R1a and R1b? Then how come my Ydna is J2a1? Is this pure luck or am I misinterpreting this?
Cheers.

[LaSentinelle]

They don't base it on your actual haplogroup. It's a guess based on your ethnicity. AKA not accurate.

But the only information they received from me was my raw DNA file. How would they know my ethnicity.

[Beowulf]

Is the Y-DNA of your closest matches only

[Lemminkäinen]

The result says only that your ancient male relatives determined by AUDNA (autosomal dna) carried those haplogroups.

[eastern]

The result says only that your ancient male relatives determined by AUDNA (autosomal dna) carried those haplogroups.

Exactly. So basically, they know your ethnicities through the raw autosomal dna file, and based on that they try to determine the haplogroup you're most likely to have.

[Jingle Bell]

Lemminkainen and VikingMallorcaSpain alr explained, but just adding that dont take MyTrueAncestry too seriously, they interesting if u dont have Gedmatch or g25 but unless that they are mostly time pretty innacurate and confuse asf

[LaSentinelle]

Lemminkainen and VikingMallorcaSpain alr explained, but just adding that dont take MyTrueAncestry too seriously, they interesting if u dont have Gedmatch or g25 but unless that they are mostly time pretty innacurate and confuse asf

Thanks for the replies! I tried using Gedmatch and the results are just as confusing. I tried using every calculator and almost all of them say that I'm finnish, ukrainian, swedish, east german, estonian or something else with 'Russian' appearing at 5+ positions and quite far removed from me. No idea why that is.
On a sidenote, my J2a1 haplogroup might be from the CHGs, since according to various Gedmatch calculators around 20% of my ancient ancestry comes from them.