TP-Link TD W8980 - Keep getting booted off network

[#1]

Just bought a TP-Link TD-W8980 N600 ADSL2+ Modem Router to replace my ancient modem/router.
My wife went through the set up process on her Mac and can connect fine to the 5GHz connection and works superfast.
I have an Asus laptop that doesn't support the 5GHz so it doesn't show up when I see which wireless connections are available. However I can see the 2.4GHz connection and when I go to select it not only can I not get online it boots my wife's Mac off the connection and then the only way she can get back on is to reset the router.
Does this sound like a setting we need to change or something fundamental!
Any help would be greatly appreciated.
Thanks

[#2]

Hi Internetted,
It sounds like this may be settings related to me, sorry this isn't something that we (staff) can't assist directly with.
You might want to try searching for other posts about the same router as you might find a member of the community that can help you out.