Dim3nsioneer

Don't you have to switch the gcode flavor to "Marlin" from "Ultimaker 2" for being able to set temperatures for an Ultimaker 2 family printer in Cura?

That is unfortunate. You may want to dump the logs on an USB stick and then send it to your reseller. He might be able to analyze it and give you a feedback what's wrong. Maybe it's the WiFi module itself. Of course, depending on what kind of engineering you are in you can check the logs yourself too. 😉

If you disable the prime blobs and put a single skirt line around your rectangle, you might loose 4mm in each direction (assuming a 0.8mm nozzle and two skirt lines; one for each extruder and a little bit of space between skirt and print). I would not call that much less.

You might want to get in contact with @korneel.

Doch. Die Kennlinien der beiden Lüfter werden nicht die gleichen sein. Da Du den gleichen Strom durch beide Lüfter lässt ergäben sich ziemlich sicher unterschiedliche Spannungen. PLA profitiert von mehr Luft. So werden starke Überhänge auf einem Ultimaker 3 mit Radiallüftern etwas besser als auf einem 2+ mit Axiallüftern.

Wenn ein normaler Travel mit retract immer noch Spuren hinterlässt, dann sollte einerseits die Drucktemperatur überprüft und ev. mal ein z hop ausprobiert werden.

Wenn Du Lüfter ersetzt solltest Du links und rechts den gleichen 12V Lüfter verbauen da diese in Serie geschaltet sind. Ansonsten bekommst Du ungleiche Spannungen (da nicht-ohmische Lasten) und dann ist der eine Lüfter dann bald mal futsch.

Combing ausschalten 😉

No, there is no way to change that on the machine by e.g. a setting. It would require a change in the firmware.

Was this a one-at-a-time print with multiple objects?

That list might be outdated. What country are you in?

Have you tried a factory reset yet?

The Cura version is the same (which?)? Or could one be Cura 4.0 and the other Cura 4.1?

If you mean the firmware recovery, no, those are two different things.

Try a factory reset.

Did you try the manual xy-setting for the z seam?

The recovery image brought you to 4.3.97? Or did you perform just the first of the two update steps? You should not print with the intermediate firmware version; there is a risk the printer gets stuck there (can be solved with another firmware recovery). I recommend to upgrade to 5.2.11. Or redo the recovery if that one actually brought you to 4.3.3.

Do you have coasting enabled?

Correct, see also

I also had that problem once with my very early UM3. Recovering the firmware image solved it:

A normal sheet of copy paper will do fine.

It's worth to try. It can fix some minor issues with the firmware. If not, then recovering the firmware with an image is the only option left. You will find instructions here on the forum.

A few months ago there were new machines without a plastic around the glass plate. Please contact your reseller about the scratches.

Did you try a Cura Connect reset yet? If that does not change the situation please try a factory reset.

The scratches are definitively not nice but I also have seen them on some new machines. What do you mean with the plastic removed? The plastic from the filament? Other than that spool nothing has a plastic wrapped around afaik if you don't count the zip bag with the tools, grease, glue stick etc.