Very interesting results, Tomenable. You are really at the crossroads of Europe genetically.
At the moment the British & Irish ancestry for anyone who has no known ancestry from that region should be interpreted as either Germanic or Celtic. In your case I'd say that you have 4.1% relating to continental Celtic ancestry (Cornwall + South Wales) and the rest mostly Germanic (except maybe NW Scotland, which might be mixed Celtic and Norse). Belgian, Dutch and Northwest German people always score very high on South England and East Anglia, so that clearly represents Saxon and Frankish ancestry.
I'm also waiting for my parents' LivingDNA results, but in their cases I only transferred their raw data files from FTDNA (while for myself, I bought their DNA kit and the results posted in the OP are based on their own raw data).
Lately I bought DNA Tribes for my parents', and it seems that this British-Irish influence in my LivingDNA results must be mostly from my father's side, while Germanic and Ugro-Finnic influence mostly from my mother's side.
Here are my dad's DNA Tribes results:
^^^ This Celtic-like influence is also visible in his Eurogenes K15:
First 4-Ancestors Oracle, then Mixed Mode from standard Oracle:
Irish, Scottish, and Welsh also shows up in his MyHeritage (but a lower percent):
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On the other hand, my mom is showing a Scandinavian or Northern Germanic type of admixture (which I kind of expected based on surnames in her family tree), as well as some kind of Baltic or Finnic (Latvia, Estonia, Northern Sweden, Finland) admixture:
My mother's Eurogenes K15 results also confirm this type of admixture:
4-Ancestors Oracle gives her 2 x Slavic + 1 x Mordvin + 1 x Scandinavin:
And my mom's MyHeritage results below:
As a side note - I wonder which part of Ukraine is "Ukrainian" sample in Eurogenes K15 from? Eurogenes K15 has in total 3 Ukrainian samples - one from Belgorod, one from Lviv and one which is labeled just "Ukrainian" without any specific info about its regional origin. What I find strange is that this "Ukrainian" sample is actually the most genetically "western" of the three - even more "western" than the Ukrainian_Lviv sample - which is surprising. You can see this in the K15 Spreadsheet on GEDmatch (compare percentages of North_Sea, Atlantic, West_Med etc. admixtures for Ukrainian_Lviv, Ukrainian_Belgorod and Ukrainian samples - unsurprisingly Belgorod is the most Eastern genetically).
Ukrainians from Lviv are significantly more western-shifted than the ones from Belgorod.
Western Ukrainians are pretty much more similar to Poles and Slovaks than to Russians.
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In K15 my dad has notably high Atlantic, my mom notably high North Sea & East Euro:
1. Father:
North_Sea 24.18
Atlantic 19.34
Baltic 24.98
Eastern_Euro 15.86
West_Med 5.16
West_Asian 4.74
East_Med 4.53
Oceanian 0.23
Northeast_African 0.96
2. Mother:
North_Sea 26.77
Atlantic 14.93
Baltic 23.96
Eastern_Euro 19.95
West_Med 5.53
West_Asian 4.42
East_Med 3.32
Red_Sea 0.24
South_Asian 0.17
Amerindian 0.54
Northeast_African 0.17
And a comparison of Eurogenes K36 admixture results (based on FTDNA raw data):
1. Father:
Basque 0.29
Central_African 0.05
Central_Euro 10.15
East_Balkan 8.33
East_Central_Euro 19.23
Eastern_Euro 13.7
Fennoscandian 11.05
French 5.28
Iberian 6.23 ---> more Iberian than Italian (I noticed many Irish also have this pattern)
Italian 3.34
Near_Eastern 1.93 ---> some kind of MENA admixture
North_Atlantic 9.1 ---> this is high for a Polish person
North_Sea 10.51
Volga-Ural 0.36
West_Caucasian 0.24
West_Med 0.17
2. Mother:
Arabian 0.65 ---> some kind of MENA admixture too
Central_Euro 8.82
East_Balkan 5.1
East_Central_Euro 22.14
Eastern_Euro 14.63
Fennoscandian 11.95
French 6.5
Iberian 2.0
Italian 6.62 ---> more Italian than Iberian (I noticed many English have this pattern)
North_Atlantic 6.55
North_Caucasian 4.14 ---> high for a Polish person
North_Sea 10.89