Recently, when writing an email, I used the following phrase:
'I hope this does not cause too big of an issue'
However, in their response, the recipient (an English teacher) said that he was 'not too sure about the grammar of "too big of an issue"' (with no further comment). However, this site seems to suggest otherwise. What could he have possibly picked out as incorrect in my usage of the phrase, and is it really significant enough of an issue to remark on in a response?
This question is not a duplicate because I'm asking about whether the phrase itself is correct, not the etymology of it. Further, it's considering the whole phrase (e.g can an issue be 'big', or should it be 'significant'?), and not just that one part.