@Royche35
The dilemma here is caused by Google Nest's design. In order to change Wi-Fi settings on the newer cameras and doorbells (and thermostats), it seems we have to remove the device from our Google account in the Google Home app while still on the Wi-Fi network we are going to get rid of, and THEN do a factory reset (either triggered automatically by the removal, or manually). See this Google Nest Help topic, for example: https://support.google.com/googlenest/answer/9223711?hl=en#zippy=
There are many postings in this forum by customers caught by variations of this, either because they moved, or updated their Wi-Fi router/mode, or the previous owner died or moved BEFORE the device was removed.
Some customers report that Google Nest Support was able to help them out of this predicament, while others say that Support could do nothing at all for them.
Did you do your removal of your camera while on your OLD router? And did you do a factory reset (or was it triggered automatically)? If you DID, then you SHOULD be able to add it back and should NOT be getting the "device is connected to another account" error.
If you did NOT, then you can't resolve it.
Either way, I think you probably need Google Nest Support's help (https://support.google.com/googlenest/gethelp) to override Google Nest's design.
