Camilla took some quiet time this morning (alog 76324),
so I reran the correlated noise budget.

The actual noisebudget traces here are eclectic, some old, some new, most are probably still from December.
Still we wanted to see if our correlated noise had changed since then (alog 76213), and the short answer is not really.

March 13 2024 Correlated Noise interactive svg

I couldn't tell what to make of this, so I compared it to our December 2023 correlated DARM.
Here, we can see our correlated noise floor at 500 - 600 Hz is moving slightly.  
If true, then it's probably not a thermal noise floor.

It's not so easy to tell if this is a calibration error, the calibration lines seem roughly similar between the two noise curves.
If this is true, then it's possible our laser noise is movely slightly, or it's something else entirely that is still not well-understood.