I have had this happening for almost a year now. It's very annoying. One day I lost my 4G connectivity and only getting H+/ 3G displayed. my APN settings are all correct as per instructions given to me. I tried calling Fido multiple times, they tried resetting the network connection on my phone several times from their end, no dice. Tried getting more Fido support, basically was told that they cannot guarantee non-Fido devices. I even tried going to the store and replaced my SIM card entirely. No luck. Can anyone help me?
I'm sorry I'm not sure what you mean by select LTE manually. Currently my network mode is LTE/3G/2G and that is the only option that includes LTE. Not sure what else to try.
With regards to inserting the sim card into another device, i don't remember if I did but I doubt the sim card is the issue because as I said I even got a brand new one and the issue persisted. I think it's something Fido specific. I went to the U.S for a visit and on Fido roaming I was connected to AT&T with the same sim card and I was getting 4G. So I believe Fido is for some reason disallowing my device from using 4G and I don't know why.
I just tried the sim card on another device and i got LTE working. Seems like the issue is with my phone exclusively, although I don't understand why because as I said it worked with AT&T and it used to get 4G with Fido up until the Nougat update...
Thanks for the update!
If your SIM allows you to get LTE in a different device, then it's not a SIM card issue. Just to confirm, have you done the latest software updates on your phone? If you did and are still having trouble, I'd suggest checking with Samsung to verify if it's a known issue!