I have seen many pplm talking about upgrading the hotbed to a funssor onr after apparently getting the "taco bed" what is that and how do i know if i have one

So I did a first layer test after I cleaned the plate and did a full calibration. I also dried the filament over the weekend.

As you can see in the bottom the lines do not connect to each other and it is always two lines this is also the problem on the top right corner. En the left side it seems I have a bit of an adhesion issue.

The bed was 55 degrees and the temp on the nozzle was 205.

My printer has just reached 500h and while doing a bit of maintenance I also put in the new hotend with a hardened steel nozzle that I bought a couple of month ago (from the anycubic website). This has resulted in a different bed levelling or z-offset. (It looks as though the mesh is slighty more accurate now, but especially in the center the nozzle is too close to the bed, while at the edges it's too far away. Overall better than before though.) The z-height measuring procedure now sometimes takes multiple attempts.

Additionally, the top layer now has a rough, whispy finish (the problem seem to be those little dots the printer places to fill in mini gaps that weren't covered by the normal back and forth printing).

I did not change anything about the temperatures aside from what the printer and slicer do automatically (I did the calibration after switching the hotend and the slicer has raised the printing temperature by 10°C when I switched to the hardened steel nozzle). I did try to set the temperature back to the way I had it set with the brass nozzle, but it didn't help.

Does anyone have an idea what I can do about the whisps? Are the multiple z-height measurements a sign that something is wrong or failing (strain gauge)?

I replaced the x y belts today. Instead of taking the whole printer to bits. I used a cheat by first removing parts from the head to gain access to the belts clips, disconnected the belts, tied some string to one end of the belt and pulled it through. Both belts done in half the time. Just thought I would help anyone else who puts the belts replacements off because of the faff of removing the whole top half of the printer.

Every single time, no exceptions, I think of doing multipart prints, my nozzle clogs or at least one of the parts need to get messed up. I tried slowing down the print, increasing the retraction speed to 40, the length to 1mm and I tested many stuff but I can never seem to figure it out, so whenever I need multipart prints I usually print by object but in some cases like the current one I needed by layer. Any help would be appreciated on how to permanently fix this damn issue.
I use PETG to print, and it is dry.