It is a strange behavior, but normally chinese companies erase the chip’s name used on their products:
Trying to protect your product using obfuscation is not a good idea, soon or later someone will figure-out it. Actually I figured the chip used on this product in less than 5 minutes (AFAIK I was the first one to figure out it).
They are using the MVSilicon BP1048B2. I also found the datasheet (brief-sheet), but didn’t found the SDK for it and how to program it.
This chip seems mostly used on Audio Sound Bars and other audio bluetooth products.
This chip is very powerful, seems a good candidate to run NuttX RTOS, see:
Update: Aaron Christophel (aka atc1441) found the SDK for this chip on github: