Stick up camera shows offline but is still working

Recently one or more of my ring stickup cameras are showing offline in the app and on my web account but they are still recording video and sending alerts so they are connected ok to rings servers. If I remove the battery and reboot then the camera works ok for a couple of days with access to its health and status. It will then just go offline and I lose access to the camera status but it carries on ‘working’. I see a few people have reported similar in the past but haven’t seen any real answer as to why this happens and what the answer is to solve it.