I own an APEMAN C770 Dash Camera that I bought from Amazon. I had an issue where the watermark or timestamp would freeze and never update. I contacted the customer support team at APEMAN and they provided me a frimware update file to fix it. After over a year of using that frimware I can confrim that the issue is no longer present.
If you like to download this frimware, you can do so here
I am not responsable if this frimware bricks your camera. This should be your last restort after contacting APEMAN at [email protected]