Fail on top layers
This is 20 hours into a 21.5 hour print. Second time this has happened. When it changes from infill (gyoid) to layers, about the second or third layer it drops some clumps, they harden, then the print head collides with it, knocking it off the plate. Raise3D Blue, in a dry box at 27% humidity. I do have some zits, so I'm working on eliminating them, and this may be related(?). Any help would be appreciated. 
If you use the cut tool in Prusaslicer and cut to leave only the region you're seeing this issue with plus perhaps another 10 mm below, are you having the same issue? Just a quick test that it's not related to the height of the object.
Formerly known on this forum as @fuchsr -- until all hell broke loose with the forum software...
Height related
I thought about that, I've yet to try it, and will. I don't think it's related to height.
Possibly the filament
I've been working on a different print with the same filament. I noticed on previous prints that this particular filament (and color) are more viscous at the normal temps. So now, I've slowed the speed to 80% (of 50) and decreased the flow to 80%. Now it's looking smoother and doesn't appear to be leaving material behind. I'll try this setup on the cut section as you mentioned.
RE: Fail on top layers
Fuchsr, I did make a cut section and printed at 80/80 as stated above. It came out pretty flawless. Now on to print the full size..