Problems connecting to home WiFi

It used to be that when I turned on my Nexus 5 in the morning it would automatically switch onto my home wifi. It still does that sometimes but not always. Then I have to enter the password to my router and click connect. Sometimes it will then connect. Sometimes I have to repeat this process several times before it connects. It will say "saved" but forgets. The phone and I are both old so I'm tolerant of forgetting. Even more exasperating is that it will automatically connect to an HP printer somewhere in my neighborhood but not my wifi. I have tried to "forget" the printer address but it doesn't go away and I don't know how I can get rid of it. Of course, if I do connect to my wifi and leave the house it disconnects. When I return I have to go through the multiple entering of the password before I can reconnect.

My isp is Comcast and the router is theirs. It was new last January so I assume it is a recent model. Android 6.01 security patch level October 5, 2016.
Any suggestions will be appreciated.
Eva