AW17 R4 - Astro A40 headset audio Issues (& Can't figure out why)

Morning all,
Hope everyone is well.

Have an issue with the audio on a 2017 Alienware 17 (Specs in the signature).

Basically my Astro A40 headset seems to have taken a strong disliking to the Realtek drivers installed, as well as standard Windows 10 ones, when it used to work perfectly a month or so ago.
I just use standard 3.5mm jacks on the left side of the machine for both input and output, however there are several things that have happened upon testing and tinkering (including uninstalling and re-installing Realtek drivers) in which the process and findings are below:

• Tried ammending the windows audio settings but all to no avail, sound was coming out of in-built speakers though.
• Headphones work but microphone does not when un-installing Realtek.
• Reinstalling Realtek Headphones work and are detected by Alienware Audio program (can select them on the pop-up).
• When doing the above, it also detects plugging in the microphone and can select that or "line-in", however neither work as they are intended.
• Ran Dell product diagnostics/support and updated to the latest Chipset and BIOS as they were a couple of months out of date.
• After messing in windows sound settings (pain in the backside in windows 10 compared to 7) I can get both working and seems fine (could record audio to test and a friend confirmed he could hear me crystal clear on Discord BUT when opening a game whilst running Discord in the background the in-game volume is exceptionally quiet even at full volume on everything (before if I ran it like that the A40s would blow one of my ear drums and on this occasion didn't hear a guy on R6Siege teabagging behind me for 45 seconds which was embarrassing).
• With the above, i had to disable the "Stereo output" playback device due to an insane echo - not sure why that was happening as I had my microphone set so I didn't listening to it (IE/ unchecking the tickbox in the recording device settings for it).
• When un-plugging the headset jack, it did not revert back to the built-in speakers.
• Restarting the machine fixed the above so it would play via in-built audio, however when un-plugging the microphone jack, I got an exceptionally loud feedback squeal which sounded like something from a horror film.

I'm running out of ideas to test/try.
I did remove a few programs when I got it such as the auto update and Tobii eyetracker as I had no need or use for them.
Any info/advice would be superb as its got me stumped
All the best