Anyone else seeing this issue?
I have the iPhone 6 (this happened on the 5 as well). When using the cellular network on 3G or LTE, it works great. When the iPhone states that i am in 4G mode, it slows to a crawl. Any idea why 3G and LTE work great but not the 4G Mode?
What's slowing to a crawl? Everything on the phone, or just those functions that depend on a network connection?
T-Mobile's "4G" network is HSPA+, and it can already hit decent speeds. Typically 3 Mbps to over 10 Mbps in my area, before it got upgraded to LTE.
I've never seen my 5s display "3G" on T-Mobile before, only GPRS, E, 4G, or LTE.
If you're having issues, I've would guess that you're just in a weak reception area. In those areas where the LTE works great, try switching the LTE off. I would guess that the HSPA+ signal strength is just as good in those areas, with decent network speed.
If you're in an area where the LTE coverage tails off and hands over to the HSPA+ network, you might end up with slow speeds no matter what type of network you're connected to.
At my office, where I have a strong T-Mobile signal, the LTE speed hits 28.5 Mbps, while 4G/HSPA+ hits 8.1 Mbps. At home, my T-Mobile signal is weaker with intermittent LTE signals. On 4G/HSPA+, the speed will hit around 3 to 4 Mbps. Go a couple of blocks over, and the LTE download speeds are close to 35 Mbps.
