I posted this in the OnePlus forum, but surprisingly not a single person replied to my thread. Considering their forum has thousands of members, that's pretty fucking poor community if you ask me. So I still need help, and am posting here because there's really nowhere else I can post it.
My carrier isn't fully supported on the LTE bands (my carrier has two bands, but the phone's cellular radio only supports one of them), but it is fully supported on the HSPA/HSPA+ bands. However, I am having issues with my data connection. I get a single bar of LTE, sometimes 2, but the speeds are lower than if I set it to 3G preferred in the Mobile Network settings. I can't even get LTE in London, let alone at my home. I have an issue with the 3G, though. Most of the time, it's in HSPA+ mode (indicated by the "H+" icon next to the signal strength indicator), however it sometimes loses the + and drops down to regular HSPA, but I don't seem to have data in that mode. I have to either reset the cellular modem (by turning aeroplane mode on and off), or wait for the + to come back. This happens several times a day, and it very rarely happened on my iPhone 3GS in the whole time I used it.
I've gone into the hidden config panel from the dialer and set preferred network type to "TD-SCDMA, GSM/WCDMA and LTE" (as people on the forum recommend), but it doesn't improve my LTE situation (I'm actually more inclined to leave it in "LTE/GSM auto (PRL)" as Europe does not use CDMA whatsoever). I'm wondering if anyone had any advice to either improve my LTE, or to eliminate the issue of not getting any data in HSPA mode. Thanks.