Cameras going on- and offline, not detecting motion

For the past several days my doorbell pro and floodlight cam (independently) have been going offline for hours for no apparent reason, and then coming back online again without my doing anything. Both are hardwired, wifi signal is fine on my phone standing next to the unit, speed 30 mbps. No “incidents” of system trouble reported. No setting changes. This evening my doorbell abruptly stopped detecting motion, even though it is online, has a signal, etc. I walked right up to it and rang the bell. It detected and announced the ring, and gave the pre-recorded announcement, but didn’t turn on the linked lights or record video. No motion shown on the timeline. Earlier this morning, it recorded a moth flying by (set on max detection). My third camera is working fine. Any ideas?