Hi everyone. Over the past several weeks my MK3 has started to skip on the y-axis, it started on a complex print, so I inspected the printer and noticed that the front idler was loose with about a 2 to 3 mm gap between it and the frame. I tighten it up and started printing again and it seemed alright till about 5 days ago. Once another layer shift occurred on the y-axis I did some reading and it seemed like there was some issue and the common advice was to disable crash detection, so for a test I did and it seemed as though the issue might be resolved. It was not, so I started to do some digging and came across a support article that mentioned the belt tension and how to check it after a self test in the menu. I ran self test and everything past, but the y axis was really close to 280 so I tightened it up by a tooth and ran self test again, it then registered 240. However, problem not solved. Today I had 2 small (different prints) shift again. So, I turned on crash detection again and printed the whistle on the sd card. The printer detected 3 crashes while printing the whistle and reentered itself. I have checked for debris, the y-axis does not have any obstruction, the belt is tensioned to spec, the rails are lubricated and everything moves freely, I have checked to make sure everything is tight, including the stepper gear and bracket, idler, frame, a basic once over of the entire printer. But I cannot print a whistle without running into several y-axis crashes. I have also updated firmware to 3.5.1. I am not sure what do at this point. I have a MK2.5 I can use, but it sees more limited use since we received the mk3 about 4 months ago. Oh, I should add I purchased the printer pre-built, but am very familiar with its workings. Any suggestions are much appreciated.