i received my H2D today and did a first layer test of the whole print bed with PLA.
The printer is fully calibrated (including vision encoder), the build plate was cleaned (twice), the filament (Bambu PLA Basic) was dryed for several hours. I tried using bed leveling set to auto and set to on.
The results are always the same. In two spots i see “artifacts” on the first layer (see attached pictures). I did the test twice and the location was the same. Bed adhesion was good over the whole bed.
You could try upping the bed temp 5-10C and see if it’s still there. It might be a cold spot that’s just not sticking as well and getting ‘pulled’ during laydown. Random (but likely since it happens irrespective of the plate) guess on things to try.
Yes! The slicer lets you specify a different flow ratio for the bottom and top layers. Bottom layer equals first layer, so that would be the one to focus on.
Also, a common way to “cheat” the problem is to use a 0.3mm first layer height rather than a 0.2mm layer height. The thinner the first layer height, the more imperfections you’re likely to see in a “perfect first layer” test.
Not sure whether the Bambu slicer allows you to change the default number of bed leveling probes, but going higher on that might also help. On a different brand printer, I got as high as several thousand bed leveling probes to address a similar issue, and it helped.
There’s at least one model on makerworld aimed specifically at finding the right flow ratio for the first layer. If it relies on Orca, though, you’re likely SOL, as I’ve already run across a case with just regular flow ratio where that is true (I document it in a different, recent thread).
If all else fails, what some people do is get a couple of dial indicator gauges, mount them to the x-axis gantry, and then meticulously level the bed manually. This reportedly works well on printers like the Qidi X-Max 3 and others where the bed leveling measurements aren’t very repeatable. I have no idea whether that’s the case here (I certainly hope not), but it’s a tool of last resort.
[ I just noticed your follow-up comment, posted just a few minutes before I posted this post, so ignore just about everything I said here, except focusing on the top-layer flow rate, if need be. ]
i did the manual bed leveling. The front left screw was already pretty tight. Still the nozzle made a small dent into the bed with the leveling gcode. I had to uncomfortably tighten the screw even further (over the limit from my POV) to get a piece of paper between the nozzle and the bed (i EXACTLY followed the steps on the wiki page). After i was done and was able to put a piece of paper between the nozzle and the bed on all 4 positions, i cleaned the plate (again) and calibrated the whole thing again.
The issue is still there. I would even say the print quality got worse in general after the manual leveling.
I already opened a ticket and will return the printer. I was also not a fan of the print quality in general. (well dryed) PLA that prints perfectly fine on my P1S is making those little hairy strings (i would not call it stringing) nearly in every PLA print. Every picture of an used H2D Nozzle i saw so far has those hairy PLA residues on it. No Idea why this is the case with the H2D. I can only guess that the print profiles are not perfect (yet)?!
Anyway. I already put more hours into this machine getting it to produce good results than i should have to. I dont want to tinker, i want to print and i expect the prints to look at least as good as on my P1S. Thats not the case.
There are also other small problems with that unit but i wont deal with those.
I just noticed your follow-up comment, posted just a few minutes before I posted this post, 
so ignore just about everything I said here, except focusing on the top-layer flow rate, if need be. ]
