This just happened again to me. Usually stable OS will disconnect from WIFI and stop doing everything! Including watering my lawn! I have to go under the house and do a power cycle to get it to connect again. This has to be fixed or I will ask for a refund on my OS unit as it is useless as it does not do what it says it will do.
Running hardware 3, 2.17 firmware with a TP-Link WAP.