I hadn't updated my software since 4.4.2 on my S5 and just updated it today. However, after updating to 4.4.4, my mobile data stopped working, I can still make calls and connect to WiFi, but mobile data does not work anymore. I even tried a factory restore but that did not help. Anyone ever experience this problem?
try this :
full wipe with wipe cache,
OTA Update not recomended.
easily, download last android version from SamMobile , then with odin flash it. check last firmware :