I'm currently working on potential fungi species and I got 3 species from the sequence result. I already constructed a phylogenetic tree with these 3 species, as well as ingroup with the most similar sequence (thx to BLAST). However, my outgroup will always be placed in the middle of the tree and not on the rock bottom. My phylogenetic tree method is Bootstrap. When I use the original tree construction, the tree seems pretty fine, but the outgroup suddenly went to the middle of the tree with bootstrap. Is there anything wrong with my choice of outgroup? Note: all of the fungi are coming from Dothidiomycetes Family with order coming from Capnodiales and Pleosperales. My outgroup however, is Mytilinidion resinicola from the same class and from Order of Mytilinidiales. I checked it before and the outgroup distance is not too close and not too far from my sample.

Thank you so much, I'm still pursuing a bachelor's degree. Sorry for this long question 😭