The filament tube between the toolhead and the top panel has a specification of outer diameter 6 mm, inner diameter 4.6 mm, length 650 mm.
Both ends are secured with quick-release fittings, which must be pressed to remove the tube.
US: https://us.snapmaker.com/products/toolhead-thick-filament-tube-6mm-4-pack-for-snapmaker-u1
EU: https://eu.snapmaker.com/products/toolhead-thick-filament-tube-6mm-4-pack-for-snapmaker-u1
Global: https://shop.snapmaker.com/products/toolhead-thick-filament-tube-6mm-4-pack-for-snapmaker-u1
After following the troubleshooting steps, if you find it difficult to resolve your issue, kindly submit a support ticket through https://snapmaker.formcrafts.com/u1-troubleshooting-request and share your troubleshooting results with some pictures/videos.
Our dedicated support team will be more than willing to assist you in resolving the issue.