The Trumas HaDeshen #88 in chelek 2, seen here discussed going to live in Eretz Yisroel in his times.
In his discussion he mentions
בני ברית מערביים נחשבים לרשעים גמורים מוסרים מפורסמים והם טורדים ומבלבלים האשכנזים שהם שומרי תורה
Who are these בני ברית מערביים and what were they doing? I'm assuming he means middle eastern Jews so I wonder if they were still practicing Judaism or perhaps they had converted to Islam. He does call them Bnei Bris, but at the same time he implies that the Ashkenzi (immigrants?) were the ones keeping the Torah. Why were these other people so intent on ruining it for the Ashkenazim?
Later on he mentions רשעת הישמעלים so these people were not Muslim, not that it's likely he would call a Muslim Bnei Bris.
A quick reference point, the author of Trumas HaDeshen Rabbi Yisroel Isserlein died 26 years before the Ottoman conquest of the Holy land, so whatever political issues were going on were still under the rule of the Mamluks