5ghz causes wireless card to crash

I purchased this router today and have been trying to figure it out. It configured fine and i can connect to the 2.4ghz ext except when i try to log into the 5ghz ext wifi it crashes my internet and i have to pull out fhe wireless card from the dock because its the only way to stop it from crashing.  I havent altered any parameters just the stock ones. my wirless card works fine on my old router for 5ghz and 2.4ghz my laptop and phone can both connect as well. is there a paramete i am missing somewhere? its taken me way to long to set this up.