I’ve been noticing some delamination (layer separation), but only on solid infill and top layers, and only on larger surfaces
Initially, I tried reducing speed, but didn’t notice any improvement
There are no noticeable issues on short lines, so I think this is something to do with acceleration, which I didn’t realise was a thing, but there are indeed settings for this in OrcaSlicer
Update:
Reducing acceleration does seem to have resulted in less severe delamination, but it hasn’t gone away completely
So I think I need to reduce it just a little bit more
The very top layer would also have high cooling fan, no?
It could be your cooling fan is just waaaay too powerful, and causing the plastic to not flow and bond correctly to the lower (or following) layers.
According to the print visualisation, there is no cooling at all on the top layer, only on the 3rd-from-the-top layer, which is right above the last sparse infill layer (I have top shell thickness set to 3 layers)