Well, having some time to dick around with this, and the issue is solved, thanks to Grobasoz. Who linked GitHub - pvvx/THB2: Custom firmware for Tuya devices on the PHY622x2 chipset this page, which contains firmwares for the sensor. It requires you to own a serial<>com device FRDI, which I do. I tinker with this stuff a lot 
Thy have specific firmware for this sensor. The OTA stuff didn’t work for me, but you can write the firmware bin to the device directly using the usb/com adapter.
This worked flawlessly and now it’s no longer a tuya device. Withouth any changes to BLE, it connects fine and I can read it’s values.