AC750 Model EX3110 5g Connection

I cannot for the life of me get my extender to connect to my 5G Wi-Fi option. I have tried resetting it, I've called into tech support and they blame my Internet provider's router and my internet provider blames the extender. Just want to be aware if anyone else has the same issue and if it's been solved. I couldn't find any forums for this particular model. I've only had it for 4 hours and I'm on the verge of smashing it.