500 Error after changing Site ID

I have no access to the network site (neither as admin nor to view the site)…

My main multisite domain had Site ID 1

While I was looking to fix an issue with wp-admin not directing into the Network site and instead redirecting (and reauthorizing) I searched the Network settings / Domain Mapping / Domains

I couldn’t find the site listed there, all other parked domain sites load

I tried adding it with and without www but couldn’t, search didn’t find the site either

I then added it as site ID 2, without the www

And instantly the site became inaccessible

What do I have to change to regain access to the site?

Please let me know if you need other details

Thank you