I've got an international edition 32GB Nexus 9 LTE. It appears to be unable to connect to 3.5G / HSPA+ networks, as a result, I get poor data speeds (3G is pretty slow for my requirements). I've got a Nexus 7, LG G2 and LG G3 all on the same carrier as the N9, and they can all connect to 3.5G / HSPA+ in the areas where the Nexus 9 struggles.
On regular phones, I would overcome this issue by dialling *#*#4636#*#* and changing the preferred bands, however, since the Nexus 9 doesn't have a dialler, I'm unable to access this menu. Any ideas on alternative ways I could get to this menu? Maybe via a third-party app or a terminal command?
I'm running Android 6.0.1 and have root access.