Need help setting the buffer size

[Djard]

In my setup, both "Input" and "Output" buffer sizes must be configured. Since the Test Tone option in Ableton 11 for me is unreliable (audio quality is degraded in recording, despite setting lowest buffer size that gives a clean, sustaining test tone), I understand that experimentation is required. But which of the two must be adjusted firstly, or do I set the Input to same size as the Output?

[Djard]

I think I figured out the problem: Ableton Live 11 that came bundled with the Focusite is not fully compatible with the USB interface. Maybe someone in the marketing department has been smoking too much weed!

[Rivanni]

Ableton Live 11 that came bundled with the Focusite is not fully compatible with the USB interface.

What does this even mean?
Why is it not fully compatible?
What exact edition and version of Live were you using?
What is the Focusrite model?

[Djard]

Thanks for responding. I'm using Ableton Live v11.3.13 Build 2023-10-17. My USB interface is a Focusrite Scarlett 2i2 2nd Gen., with the latest driver, v.4.119.13_33.

Because I experience no difficulty with record and playback when using Audacity but cannot do the same with Ableton--without having to configure audio setup for recording then reconfure for playback--it seems to me Focusrite is not fully compatible with Ableton. But I must be mistaken, since others do not experience this limitation.

In Windows' "Sound" settings, I have Focusrite as the default recording device and Realtek Speakers as the default playback device. Below is what I get when configuring Ableton to work with the Focusrite interface.

Driver Type: ASIO
Audio Device: Focusrite USB ASIO
RESULT: No "Audio Output" setting appears; so while I can record my guitar, without interference from the internal PC mic, playback is unavailble. To play back what was recorded, I must go into Preferences again and reconfigure as follows.

Driver type: MME/DirectX
Audio Input: No Input (I get feedback if Focusite is selected)
Audio Output: Realtek...Wave (or DX)
RESULT: Playback of a recording is possible; but to record again, I must reconfigure setup in Preferences again. Sigh!

Driver Type: ASIO
Audio Device: ASIO4ALL v2
RESULT: Records through the internal laptop mic, which cannot be turned down or disabled, even with Focusrite selected as the default recording device. To use latest driver from Focusrite, ASIO4ALL had to be uninstalled. It also seems incompatible with my system.

I would like to be able to record my guitar then play back what I recorded, without having to reconfigure audio setup each time. Can someone lend me a hand?