@Pbaker 

So you are using the hotspot as the internet source connected to the Range Extender and then the Rotuer as an AP to the Range Extender?  Is that correct?  If so lkely the issue is going to be the ammount of devices connected to the hotspot, which is further impacted by the half duplex nature of the Range Extender.  

@Carl 

Yes my Hotspot is the internet source. The range extender connects to that and I use a cat 5 cable to a router that is the AP to all of my devices.

This setup worked great when I had a sprint sim in my phone and still works great with my wife's phone.

Now that I have a T-mobile sim everything but my switches, plugs and camera work online.

The router was put in place to bypass the 8 device limitation on the mobile Hotspot.

My phone only sees the range extender and router and doesn't see all the devices connected to the router.

Let me get this straight... You're using a router to connect to a range extender to connect to a cellphone to get to the INTERNET??  Isn't that exactly backwards?

@DBF 

Yes I use a router to connect all my devices to and it allows me to block things from the internet such as my cameras so they are only viewable on the LAN.

I also live in a rural area and a cellphone Hotspot or satellite internet is the only option for internet. Yep you read that correctly there are places in the USA that does not have internet. 

So I connect the router to the range extender as I haven't figured out how to connect the router to the phones hotspot directly.

@Pbaker 

The likelyness of this setup having issues is high.  This is because Cellphone hotspots aren't designed to have mulitple devices connecting at a time.  On top of that a range extender will reduce recieved speed up to 50% then you have the router communicating with the majority of the client devices directly and relaying that through the ethernet connect to the range extender.  its a very unique setup and one that will not be with out problems.  I would recommend by starting to remove the extender.  On the router look for one of two features.  1.  Opperation mode for Range Extender or WDS bridging.  Both features will have the router act as the range extender.  While the speed issue will still be there you will remove 1 link in the chain and help mitgiate the latency and potental issues.  This is probably the only advice we can give in a situation like this.    I can understand the issues of living in Rural America.  My mother lives in a rural part of Roy WA where Satalite is the only internet choice and I have had to tell her to limit her device activty to one device at a time because of it.  The real fix is when the infrastructure finally makes it to you and you then finally have high speed access.