IPad 6th gen. WiFi doesn’t stay connected.

My iPad 6 doesn’t stay connected to WiFi. If I stop using it for a few minutes and come back to it I have to manually reconnect in settings. It use to connect automatically. This is on 3 different WiFi networks including my home one. This started a few weeks ago and has never been a problem before. I have rebooted it several times and turned it off for a day and nothing seems to work. Software is up to date. Any ideas? Thanks!