I had the double on and upgraded firmware to 21.
Then I put the single back on (been printing extremely reliably on earlier versions) and ran levelling.
Instead of doing the little jogs up and down at each step, it does the first one directly, then each subsequent step it just goes up. And then up for the next one.
Only option is to revert or manual.
This is an elementary check that should have been done before issuing the update. Check on all your configurations, not just the shiny new bit.
Can confirm 1.15.20 works
Seems to be an issue with machines that have attached the DE. I have only the SE and 1.15.21 has been working perfectly normal for me.
I think installing the DE does a lot of strange stuff - I don’t know if it remembers the K settings etc either - since installing it the build quality on the single extruder has been rather patchy.
There are also some issues remembering the Z offset - every time I turn it on I have to lower Z-offset by about 0.5mm.
But thanks for the info, it is good feedback for those who haven’t bought the double extruder so they know they can safely upgrade. For those with it I guess we wait again. I use the single extruder because it is faster (lighter) and I have a number of repeat models that I can pretty much just press go on.
Definitely write support about it.