Been a Fido customer for about 6 years now and I never had this problem before about 2 months ago data start running slow around 1-3 mbps use to run in-between 30-40 mbps, I'm in a rural area but never had this problem before, even with 3 to 4 bars still runs very slow.
Welcome to the community!
If you restart the phone does the speed increase? You can also try taking out the SIM card then putting it back in and see if it helps. You can also try doing a network reset and also you can contact customer service and ask them to do a reset to switch on your line and see if it helps.