Very low sound from sony tv bluetooth output to sony headphones compared to headphone socket output

[JohnR3]

Audio level on sony tv bluetooth output to my sony headphones very low (indicated setting 98) compared to output level from headphone socket (indicated setting 22) I have varied out factory resets on tv and headphones numerous times

[JohnR3]

Sony authorised engineer called. He was unable to improve on the low Bluetooth volume issue. Also, he suggested I visit retailer and check Bluetooth headphone output on other Sony tv sets which I did. Even on the latest Sony models the low Bluetooth headphone output is low, the retailer needed the volume setting to be 76. So it seems that this is a  Sony issue that has been present on Sony sets for ages.