Unreliable Wi-Fi is rarely just an internet problem. It can come from poor access point placement, overloaded equipment, interference, old cabling or a network that has grown without a plan.
Begin by mapping where people actually work. Note dead zones, meeting areas, printers, cameras and any equipment that needs a wired connection. A simple map is often more useful than another speed test.
Next, review the equipment and configuration. Separate guest access from business traffic, update firmware, use strong administrator credentials and avoid hiding a capacity problem behind a second cheap router.
If the network supports your business, document it. Labels, passwords stored securely and a simple equipment list make future support faster and less expensive.