Wi-Fi and app connectivity problems frustrate robot vacuum owners more than almost any other issue — partly because the fix is rarely where it seems. The robot appears to be the problem, but 70% of the time the issue is the home network: a 5GHz-only connection, a router's MAC filter, or a recent ISP router replacement that changed network credentials.
Every consumer robot vacuum on the market uses the 2.4GHz Wi-Fi band exclusively. Modern routers broadcasting combined "smart" networks that automatically switch devices between 2.4GHz and 5GHz will prevent robot vacuums from connecting — or connect them temporarily before dropping the link when the router decides 5GHz is better. The fix is to create a dedicated 2.4GHz SSID in your router settings and connect the robot to that network.
App connectivity failures are often confused with Wi-Fi failures, but they have different causes. If your robot shows as connected in your router's client list but the app shows offline, the problem is typically: (1) the app cached stale credentials after a firmware update, (2) the cloud server is temporarily unavailable, or (3) a VPN on your phone is interfering with the local device discovery protocol. Signing out and back in to the app, or disabling the VPN, resolves most of these in under two minutes.
Smart home integrations (Alexa, Google Home, Apple HomeKit) add a third layer of potential failure on top of the robot and the app. When "Alexa, start cleaning" stops working, check the integration first — not the robot. Re-linking the skill in the Alexa app, or the Action in Google Home, is usually the fastest path to a fix.