House flies

My wife and I have been dealing with house flies recently in our house. We live in north Fort Lauderale and there is a canal behind us. Last North around this time we had a similar issue that eventually went away but this year we are dealing with even more. We have been killing roughly 7+ house flies a day. They seem to be coming out when we start cooking inside.

We keep a very clean house, we had an exterminator come out and inspect the house. He checked the outside, inside and went up into the attic. He couldn’t find anything wrong and sprayed the attic to be safe. He recommended using a fogger but we wanted to avoid so many strong chemicals going off, we have a dog.

After he couldn’t find an issue I put a trap in the far backyard about 20 ft away. The photo is the trap after 3 days.

We are going crazy still killing all these flies and can’t for the life of us figure out why, the exterminator had no idea either. Wanted to see if anyone else has dealt with this issue and had a recommendation for us. Thank you!