2007 Yukon Denali Remote Keyless Entry Issue

So I purchased my Denali about a year ago. Everything was working fantastic. About a week ago, my keyless entry system began not working on both FOBs. I changed the batteries in both and checked the fuse, and still the same issue.

Basically, the FOB would work either when I put the key in the door or immediately after I open the door. Anything after about 2-5 minutes after I leave the car, the FOBs become inactive.

I took it to the dealer and they ran the diagnostic test on my car and told me that there was a transmitter issue. I found that odd, seeing that BOTH of my FOBs were working last week, and now they are not. They sold me a new FOB and low and behold, it did not work.

Anyone else experience these issues? Any help would be greatly appreciated! Thanks.