Here is my observation. I have yet to see an American flag flying at a house that has a Biden sign. I make a special point to check. Check it out for yourself and tell me if you do not get identical results.
The flags that have Biden signs are rainbow flags or hate has no home here kind of things all around. No American flag visible where Biden signs are. The thing that worries me (just a tiny bit) about one house in particular, is that the man in that house is a Protestant preacher here and he is very popular. Of course, wouldn’t you know, right next door is the Sheriff, with an American flag on a pole. Amazingly the county judge lives next door to the sheriff, and he has an American flag hanging from his front porch. Kinda funny, but everyone is cordial and gets along pretty well, at least to the outside appearance of things.
There is a house a few blocks from me with an American flag and a Harris Biden yard sign.