Proto-Bulgars were an Irano-Caucasian people(?)
It seems that Bulgarians are modelled not just as Thracian+Slavic but they need an extra Irano-Caucasian reference.
Target: Bulgarian
Distance: 2.2213% / 0.02221322
50.2 BGR_IA
33.2 HUN_Avar_Szolad
16.6 CZE_Early_Slav
Target: Bulgarian
Distance: 1.3949% / 0.01394875
42.6 BGR_IA
42.6 HUN_Avar_Szolad
14.8 RUS_Alan_MA
Alan_MA reference is a mix of Sarmatians and native Caucasians. If instead of Alan I use Western Scythians and pure Caucasians the distance is even smaller
Target: Bulgarian
Distance: 1.2370% / 0.01236978
42.6 BGR_IA
35.0 HUN_Avar_Szolad
14.8 Scythian_UKR
7.6 Georgian_Imer
Target: Bulgarian
Distance: 1.5536% / 0.01553649
52.0 BGR_IA
35.8 HUN_Avar_Szolad
12.2 Sarmatian_RUS_Caucasus
It seems quite possible that Proto-Bulgars were similar to Medieval Alans and Sarmatians who lived near Cauacsus and not a Turkic people.