UM3 calibration issues

[paoletto 3]

Hi so i've been successfully printing (pretty much since print 1) with my ultimaker, quite intensly for a couple of weeks.
Then i stopped using for a while, simply unplugged (with filament left in), and parked.

Today, after a bit (4-5 weeks) i switched on again and tried to print.
First thing i noticed is a slightly different sound and a somewhat slightly different autocalibration pattern.
Then i notice that, while it used to autocalibrate with the (unused) printcore 2, now it uses the first printcore to calibrate.
It also produces the print blob differently, making a much larger puddle in the beginning before starting to lower the bed.

And this is what i got out of it: https://imgur.com/a/eFAnxUl
It never happened to me before to see such corners lifting up.
The attempt in the picture was done using layer height 0.32, line width 0.32, print speed 40mm/s, temperature 207c.
I'm not sure if there's something i am doing wrong.
In the meanwhile i tried to unload the material, take out and in again the printcore1. i managed to get a decent print of a simple part, after,

but calibration still done with PC1, and the printer even complained once of too large difference between PC1 and PC2..

Ideas?