Some likely did worship Egyptian gods. The Omrides worshipped Yhwh ...despite what the book of Kings tells us. But yhwh was one on the 70 sons of El and likely came from south of Edom...prehaps near Egypt.
Yes the Iao issue is easy.... before the Hasmoeon dynesty I dont think there was any issue whose god you worshipped. That one family of priests took control of religion.
We know certian houses in Israel and Judah in pre exilic timnes worshipped yhwh but not as anymore then a war god.
In the Persian era yhwh was worshipped however likely zorastrainism contributed to monotheism becoming norm.
The hellenistic era prior to 150 bce was a mixed bag likely. For instance the was astatue of moses on an ass in the temple in 200bce lol