Good news, looks like they have an app that you can check and see which bars to avoid! Hahaha

Gross

You and me both, im suffering the same issue. Things to check, temperature, extruder settings, check to see if you say extrude 100mm you actually use 100mm. Tightness/cleanliness of the extruder drive, tightness of the nozzle (check this when the extruder is up to temp), and probably a ton of other things im not thinking of right now