What about the photos from both sides?

I would also recommend to do a general printer maintenance check especially for short and long PTFE tubes.

The through explanation is under https://forum.prusa3d.com/forum/hardware-firmware-and-software-help/how-often-to-replace-various-parts-on-the-mini-a-proposed-regular-part-replacement-schedule/

The first layer 'Z' offset is probably OK for a smooth sheet but textured print sheets need a fraction more 'squish' than smooth ones.

The poor adhesion looks like the result of a dirty print sheet - but it's hard to be certain with damp filament, it won't hurt to give the sheet a thorough clean.

White/pastel filaments are always trickier to print with than natural/dark colours.

Cheerio,

@_KaszpiR_ posted official instructions above, that may be worth a read. My advice is generic, not for this particular printer.

If you want to print test chips like the one you're holding (and maybe half the size then it's four times faster), you may slice for a lower layer height just to set Z-offset (it gets more sensitive so the change from Z offset is observed more clearly). When happy with the result, print the object with the original layer height, Z offset remains unchanged.

And did I mention, dry (and I mean "really" dry) filament matters...

Edit not sure if the Prusa GUI allows 0.1 mm, might be hard without GCODE command line. You could set Z=0.000 mm and do the above alignment, then move down by 100 µm.