mobile

Hi, I was told to post my question here. I bought my Note 3 with AT&T but switched to T-mobile with sim unlock. The device runs fine. My device is currently running N900A....NC2 (4.4.2). It is rooted, however not much has been done after rooting. I'm able to download OTA update. However, the installation fails after 25%. It is unclear if it is because I'm no longer with AT&T or is it because my device is rooted. I tried calling T-mobile but didn't get much help from them. What are my options at this point? I'm pretty new at this so any help is appreciated. Thanks in advance.