What tipped me off was the increasing frequency of dropouts over the past month or two

What Orbi model system do you have? 

What FW version is loaded on the system? 

Something you should try, manually re-loaded the FW using a wired PC and web browser on to the system. We've seen odd problems appear if a orbi system is auto udpated. Manually loading FW using FW files seems to have better results and less problems. I always manually load FW on my systems. Power cycle afterwards, then if problems are seen, do a factory reset and setup from scratch. 

Procedure to Manually Firmware Update Orbi and Nighthawk Mesh systems. | NETGEAR Communities

What do you mean by drop outs? Need more details on this.

How many RBS are deployed? 
What is the size of your home? Sq Ft? 
What is the distance between the router 📡 and satellite(s)🛰️? 30 feet or more is recommended in between RBR 📡 and RBS 🛰️ to begin with depending upon building materials when wired or wirelessly connected. 
https://kb.netgear.com/31029/Where-should-I-place-my-Orbi-satellite ‌‌🛰

Does this happen with the RBS turned OFF? 
Does this happen with both wireless and wired devices? 
What channel configurations are currently set on the router? 

Be sure to disable any MAC Address randomizers on phones and pads while at home:
https://community.netgear.com/kb/en-orbi-knowledge-sharing/netgear-mobile-applications-and-androidapplewindows-devices-faq/2457046

What is the Mfr and model# of the Internet Service Providers modem/ONT the NG router is connected too? 
Be sure your using a good quality LAN cable between the modem and router. CAT6A STP is recommended. 

Please post a copy and paste of the modems connection status and event log page.
https://kb.netgear.com/30007/How-do-I-obtain-the-cable-connection-information-from-a-NETGEAR-cable-modem-modem-router

https://kb.netgear.com/30008/How-do-I-view-or-clear-the-event-logs-on-my-NETGEAR-cable-modem-or-modem-router