I don't see the issue.
"Pater" became in romance languages various words: pai (Portuguese), padre(Spanish, Italian), père (French).
Most of these languages have endearing forms that are variations of "papá"(Spanish, Italian and French), "papai" (Portuguese).
In most of them "padre" is the word for a RC or OC priest. In French it's "prêtre", clearly a variation of the same.
Also, in most of them "Pope" is translated as some form of "Papa" (the endearing form), again, in French we have "Pape", a slight variation.
So, with the exception of bishops all are called "father" in daily life. The Greeks here do call the father "papá", although the accent, in Portuguese, differs from the word for "Pope" which would be "pápa".