I will concede that his "s" sounds a little off.

Mexico, sleeping, recommends, percent, strong, speech, tax, tips... these words are coming across strangely.

EDIT - the more he speaks, the easier it is for me to hear it. There are other sounds as well... the g/j ("gee" / "jay"). "Sh" at the beginning of she or share. Good observation, OP.

I will concede that his "s" sounds a little off.

Mexico, sleeping, recommends, percent, strong, speech, tax, tips... these words are coming across strangely.