Sorry this might sound like a rant. But I am posting to see if anyone can help me or give suggestions. Very frustrated right now. I'm having what seems like belt tension problems and nothing is working.

This is a core one kit I finished about a week ago.

I spent about an hour or two just trying to get the y axis calibration done and tensioning and re-tensioning until finally the lower belt pulled right out of the carriage.

I called it quits as it was late. Picked up again after a week. Disassembled the nextruder, reattached the belt, this time pulling a few more teeth through.

Then I spent about 20-30 minutes getting the tension within 1-2Hz, around 84-85. it would not pass the test and I remember seeing posts saying that factory printers are coming with asymmetrical belt tension, and they favor no-play on the y axis when the carriage is pulled all the way forward. I had a tiny tiny bit of play. Maybe less than 1mm so I tried tensioning the side with play just a touch until it was completely gone.

Then retried the calibration and everything passed...

Printed a handful of things, little kit cards, some filament clips, the stock keychain file, and also pretty decent looking benchy.

I could not use the stock file on the benchy because every single time I ran it it gave me layer shifts after the first layer????!!!

After printing the successful benchy I wanted to start printing some fidget toys. I tried 6 separate times with a couple different files and every time the print had a layer shift within the first few layers, sometimes more than one shift. This is using file sliced in prusaslicer, had tens of thousands of builds so I thought the model would be good.

I reran the calibration tests, y axis passes no problem. X axis will not pass. Its really strange. It goes to the right side and bumps but about halfway on its way to the left side it just stops and instantly fails, every time. It doesn't even get close to the left side. I thought maybe the cables are obstructing it, I pulled more slack out and it's still failing. So I went back to tensioning belts again...

Again I tried prioritizing 85hz for both sides and it fails again and again. I tried prioritizing zero play in the y axis and it fails again and again.

I don't know what to do. From my research it seems like support is not all that helpful on this topic and I'm not looking forward to going back and forth with them trying everything I already tried... I keep hearing people talk about bending the flimsy L brackets into square, and I don't think that's my problem as I have very very little play even at 85hz on both sides. I checked them with a square and they seem pretty spot on. I think that would affect y axis only too. Running these calibration tests again and again is taking a toll on my mental health.

Is anyone having as much trouble as I am? I feel like I am losing my mind. I purchased this as my first printer because of the prusa name and reputation I chose to spend a premium over creality and elegoo machines because "it just works" they all said "it's a workhorse" they said.

Core One kit issues driving me insane