A restart that temporarily restores connectivity is an observation, not proof that the router is the cause. Record the time, duration, affected devices, and whether wired and Wi-Fi connections fail together.
Record useful differences
An issue affecting one desk can point the investigation toward its device or physical connection. An office-wide loss of external access may justify checks of the router, WAN, and ISP. Physical checks may still be needed.
Ask which alerts your setup supports
UniFi Alarm Manager documents internet event categories including WAN offline, latency spikes, and packet loss. Exact availability depends on the gateway and software. SonicWall monitoring options should also be confirmed and tested for the actual model, management tools, and licensing.
Define the response
Agree on who receives an alert and the hours when follow-up occurs. Supported checks can provide more visibility between visits; they do not guarantee uptime. Ask about TechWorld Care if you want the device checks and follow-up to have an ongoing owner.