I made a post previously how I never was assigned any Balkan in 2018 with 23andme (I no longer have the account or any account with commercial tests). But I get given Balkan with every other site I have used such as YourDNAPortal, mytrueancestry, DNAgenics, sequencing.com, Geneplaza and DNa.Land. And it always ranges between 10-15%. I was looking through my relative matches with DNA.Land last night and I have 50, the majority having typical British surnames which I expect because my mothers side is pretty much almost all British. But there are few matches that have Romanian first names and surnames and they are predicted as my 3rd cousin once removed. When I had my MyHeritage account and I used the option to see how many of my matches had Balkan DNA I had around 400 matches.