the “other side” of the house… some tiny drywalls or reinforced concrete loadcarrying walls are totally different.

Do not forget, the further away you are from your own wifi point, the closer you get to your neighbour’s.

Your situation might be more about your neighbours wifi than your own. Start with choosing a wifi channel that has no or little interference with the wifi points around you.

please, use the android app.

ios/apple does not allows an app access to the wifi controller in the way is needed to obtain the data.

There is a good reason my advise is: use android app wifi analyser. Steal/loan/borrow an android device. your iphone is not going to help you.

android app wifi analyzer.