Ehh, Somalis are more 55-60% Nilotic and 25-30% West Asian/15% North African. However, I recall Somali Kenyans having slightly elevated levels of SSA.The proxies you've chosen is really poor, it's misleading but Eritreans have high Eurasian admixture. They were connected to yeman during their empire especially the Axumite period. They have 25% Arabian compared to 3% for us somalis. So the question is, why are they 15% more eurasian than somalis when it should have been 25% because of their MENA dna.
Somalis ancestor is 60%Nilotic+ 25% north african + 15%MENA whereas Habasha are about 1/4 Nilotic+1/4 Omotic+ 1/2 MENA.
I agree with the autosomal DNA for the reason of your phenotype but Eurasian:Sub Saharan admixture or haplogroup type has nothing to do with phenotype. Some Eritreans have soft hair but it's uncommon for Eritreans to have waves or loose hair, thats why they prefer to have the 1970s afro hair. Compare to somalis it's more likely we have loose curly to wavy hair types like 2A 2B 2C, 3A 3B and 3C. So maybe the culprit is the Omotic admixture or maybe there is other reasons not known yet.