Fluctuating AFR on light load

[Tapi]

It's been few years since I last tuned my car, simply because I haven't felt like it needed any tuning. The Hptuners V3.2 needed some attention from me and while I made suitable layouts, I drove a 15 minute log with it. This rise some questions:

Why is the AFR (wideband) fluctuating when I'm cruising with light throttle? I'm quessing it has something to do with LT headers having the narrowbands so far away from the engine? I noticed it makes AFR error logging inaccurate. How would you take care of this?

The car has Maggie, cam, 2 bar SD tune and LT headers.

Log and the layout attached.99 avo 2016 1.hpl99 avo scan1.Layout.xml