Sound issues Win 10 Bootcamp

Ok this is a strange one 2020 Imac 27' running in Bootcamp (installed via App) everything goes well for about 3-4 weeks to a month and a 1/2 then the Sound goes without warning (one day its fine next Boot nothing), yet the sound still works with the Headphones.

PRAM\NVRAM\SMC reset, numerous reinstalls os Win10, ran Bootcamp repair (software downloaded through the Mac Bootcamp App) installed Cirrus Drivers (CirrusAudioCS4206x64) and comparitive Realtek Drivers (Generic Setup S\Ware), ran the usual Windows troubleshooters in Win10 (normally useless and on this occasion fruitless) in Devices Manager menu deleted, uninstalled, updated Drivers.

Casting my mind back to the early days of "Windoze" you could manually adjust IRQ settings for errant devices, is this still an option?

Any ideas or Suggestions apart from "go buy some Speakers or just wear Headphines" lol ? Would be gratefully received. 😃