Default LTE bug

Hi I seem to have a problem getting LTE. I'm using a galaxy s3 i747m on Fido and I'm using stock Rogers ROM. I have a problem with LTE. I used to get it everywhere most of the time but it now only works once in a while. When I do finally get LTE it only works 30% of the time. I have full signal LTE but it doesn't load any webpages or anything. Once and a while it does though. I have tried bootloaders, modems, different Roms and I can seem to solve this problem. Does anyone know how I can fix this?

Thanks. I need my stable LTE back.

Sent from my SAMSUNG-SGH-I747 using XDA Free mobile app