IPTV streaming not working with 1g fiber

 It depends on the quality of streaming. But minimum speed for standard definition is 3 mbps, for HD quality it's 5mbps and for ultra HD quality it's 25mbps. 

Please explain what "not working" means in this case.  Do you get messages?  What are they?   What has the IPTV streaming support said about your problems so far?  What steps have you taken to troubleshoot so far?

So I stream off firestick and was advised most iptv streaming from firestick work only at 2.4ghz. So my fiber 1g is too fast. AT&T was able to set me up a work around Wi-Fi to work at 2.4ghz. It worked for about a week. My iptv service have no idea how to help me. When I say does not work means I can’t logon to iptv service to watch a show/movie.  

When you say "can't logon", can you be more specific?  The login screen doesn't show?  You get an error message?

Amazon FireTV Sticks have all had the capacity for 5 GHz and 2.4 GHz.  This is not to say that you'll have trouble free performance with either band, and you are much more likely to have issues with 5 GHz than 2.4 GHz (because the higher frequencies don't travel well as far, or penetrate walls and similar obstacles as well).  FireTV sticks have never had stellar Wi-Fi and their location next to a big TV screen (often between them and the Wireless Router/Gateway) doesn't make it any easier.    So... locking them on a 2.4 GHz band isn't a bad idea, but it does mean no 4K content (assuming that you even have a 4K fireTV stick).  Using a USB->Ethernet adapter with them isn't a bad idea either (it makes my FireTV Cube a lot more reliable), if you can accomplish that.