Re: Activated Sprint Spark on Nexus 5 but...
It could be your area, in NYC I'm able to use band 26 aka 800 MHz lte indoor, the same with 1900 MHz, & outside it uses band 25 & 41, being 1900 MHz & 2.5 GHz. I had to wait for the android 4.4.3 update to use spark, which one are you using? Because anything less well only let you use 1900 MHz LTE & I don't know if it users 800 MHz got just voice or not at all for anything.
It could be your area, in NYC I'm able to use band 26 aka 800 MHz lte indoor, the same with 1900 MHz, & outside it uses band 25 & 41, being 1900 MHz & 2.5 GHz. I had to wait for the android 4.4.3 update to use spark, which one are you using? Because anything less well only let you use 1900 MHz LTE & I don't know if it users 800 MHz got just voice or not at all for anything.