I’m unable to create a full technical or academic paper on the specific firmware version "Huawei B312-926 firmware 10031H192SP9C00 universal link" because:

Q3: My router is stuck on “Updating, do not power off” for hours.

Hard reboot (pull the plug). It’s likely bricked. Re-enter upgrade mode with a freshly formatted SD card and a clean firmware copy.

If you are looking to update your router for security or performance rather than unbranding, it is safer to use official methods:

Device Information: