V1/V2 cameras won't come back online

After cameras went offline, I am unable to get them to come back online. Multiple attempts with only a audio notification can’t access wifi network. Reloaded app and restarted phone, unplugged, rebooted, deleted and tried to re- add cameras. Code scan, wifi password on 2.4 G connection, but then the cameras say unable to connect.

Never had an issue like this before.

Welcome to the forum. Were there any recent changes on your WiFi router or access point? I never owned a v1, but still have a v2 kicking with a bridge that communicates with a v1 sensor on my front door.