I agree with ophadece on that matter (100%). Since, the mid 19th century's attempt to revive Coptic language, there have been a lot of uninformed and misinformed articles, and books overstating the influence of Coptic on Egyptian Arabic. At its peak, some claimed that there are 10,000 Coptic words that survived in Egyptian Arabic. I would not mention names in public to avoid defamation.
Also, there have been attempts to translate Egyptian Arabic proverbs to Coptic with subsequent backdating of proverbs as well as providing false etymologies.
The net result is a lot of false etymology, confusion and misinformation. This really does not help any learner and does not reflect well on the status of Coptic teachers.
For Egyptian Arabic words of Coptic etymology I would highly recommend:
‘The phonetics and phonology of the Bohairic dialect of Coptic and the survival of Coptic words in the colloquial and Classical Arabic of Egypt and of Coptic grammatical constructions in colloquial Egyptian Arabic’. Dr Emile Maher Ishak (PhD thesis)
Bishai, Wilson B (1960).
Notes on the Coptic substratum in Egyptian Arabic. Journal of the American Oriental Society 80(3):225-229.
Bishai, Wilson B (1961).
Nature and extent of Coptic phonological influence on Egyptian Arabic. Journal of Semitic Studies 6(2):175-182.
Bishai, Wilson B (1964).
Coptic lexical influence on Egyptian Arabic. Journal of Near Eastern Studies 23(1):39-47.
This is a link that provides these sources
https://copticsounds.wordpress.com/resources/