Well, what is the country that is configured on the device?
How far the devices from the WAP?
I would suggest two things:
First: to move your thread to small-business wireless forum. They can help you better.
Second: try upgrading the firmware on your RV220W device to latest.
HTH
Amjad
Rating useful replies is more useful than saying "Thank you"
Rating useful replies is more useful than saying "Thank you"