Possible engine sound bug for rocket planes

was playing 6.7 in the spitfire when i encountered a BI, realized i couldn’t hear him approaching at all and died when he later got on my tail and i had 0 sound clues, decided to test drive it and could only hear it when i turned my volume to 100. (i usually have it on 3 and that is more than enough to hear basically everything for me) same thing for the ME-163, not sure if i am misremembering but i stg those planes were not that quiet before