Ender3 Pro edges curl on prints at the plate

I use Cura for slicing, with an Ender 3 Pro printer, using the stock magnetic plate. Often, but not always, the edges that touch the plate/bed curl.
My typical setting is 60 degrees for bed/plate and 200 for the nozzle.
I've played with initial layer settings, trying to make the bed cool after 0.4mm... but, that only helps a little.
I'm attaching an image of one my models, and you can see what I'm referring to.
Can someone definitively tell me what's going on here?