Firmware is the permanent software programmed into the device's read-only memory. Unlike an app on your phone that you can easily delete, firmware is the operating system that tells the hardware how to function.
If you are unsure what firmware is currently running on your device, you can easily check it: e5577fs-932 firmware
New firmware may have reset your APN settings. Go to Settings > Network > APN and re-enter your carrier’s APN (e.g., internet , www.globe.com.ph ). Also, check if “LTE Only” mode was disabled. Firmware is the permanent software programmed into the
Write this down. You will need it to verify compatibility. www.globe.com.ph ). Also
Avoid random file-sharing sites (4pda, Google Drive links from forums) unless you absolutely trust the source. Malicious firmware can inject backdoors or permanently brick your device.