Huawei produces different hardware revisions of the HG8321R (e.g., V3, V5). A firmware file meant for V5 will fail or corrupt a V3 device. Check the physical sticker on the bottom of your device to find your exact model and hardware version.
If your ONT randomly reboots or drops the GPON connection (LOS light blinking red), a firmware update can resolve memory leaks. huawei hg8321r firmware download
close the browser window, refresh the page, or unplug the ONT. The process typically takes 3 to 5 minutes. Huawei produces different hardware revisions of the HG8321R