At least one repeater is in use on the WiFi network.
Take the WiFi repeater out of operation temporarily so that the hob and the cooker hood are physically connected to the same radio cell.
If taking the WiFi repeater out of operation temporarily solves the problem, check if the WiFi repeater can be configured with its own WiFi network (SSID). Then connect the hob and the cooker hood to your WiFi network (SSID).
Alternatively, you can attempt troubleshooting as follows:
Despite logging on successfully, Con@ctivity is inoperative
The cooker hood does not switch on until several minutes after the hob has been switched on