Iphone XR - ios 16.6 update - home wifi network no longer auto joins/also drops for no reason

I have a family of 4 iphone XR's. 2 of them updated to 16.6 about 2 weeks ago and both users immediately noticed that when leaving home and coming back, the phone would not auto-join the home wifi network. I tried the often mentioned topics of: make sure wifi is working, make sure auto-join is checked, reset network settings, etc. and other than temporarily working until we leave the network (leave home) and when we arrive back - back to the same problem. I then decided to update a 3rd phone to 16.6 to see if I would have that same problem. Sure enough, after the update this phone now has the same problem. We have not updated the 4th phone to help prove that it is not our wifi network or cell phone provider, that 16.6 did something to cause this problem. Any thoughts on what might need to be changed on the updated iphones to make it work or what needs to be down to the router to maybe assist the phones?