Try these tips to fix wifi connectivity problems.
"Forget" all but your primary network
In the device settings, go to the wifi menu and confirm the device is connected to the correct network.
For every other connected network, select "Forget" or "Forget this network". This stops the device from switching between signals.
Check network frequency
Test different network frequencies. Some people think that dual band works better on 2.4GHz. Others prefer 5GHz.
Set a dedicated network and channel
Larger offices get better results when the devices are on a semi-private network. A shared network can have hundreds of employees and thousands of other laptops, tablets and phones.
Upgrade your OS
Some older versions of Android and iOS have known wifi issues. An OS upgrade may help.