I see this behavior almost every day. It is IMHO some kind of "loading" bug. They are real portals, not removed. Just the scanner does not render an object of portal (just XM dots around). One has either to switch to other portal or even app and back (force some reload) or access the portal using a key (remote view) and then operate the portal as it is within a range. BUG for sure.
Comments
Un portail valider et réel pas un fake n'apparaît plus dans Ingress.
Not a bug, report wrong removals at https://community.wayfarer.nianticlabs.com/
I see this behavior almost every day. It is IMHO some kind of "loading" bug. They are real portals, not removed. Just the scanner does not render an object of portal (just XM dots around). One has either to switch to other portal or even app and back (force some reload) or access the portal using a key (remote view) and then operate the portal as it is within a range. BUG for sure.