I have a very drought tolerant type of fescue and had issues with browning this year.
No matter how much I watered it was still not recovering.
I ended up calling a grass treatment company and it turns out I have an infestation of chinch bugs.
We looked at some extra dry spots and they were easily visible.
They end up attacking the grass and it looks exactly as if your lawn needs more water.
You may want to look into that aspect as well.
https://www.canada.ca/en/health-canada/services/pest-control-tips/chinch-bugs.html