In some cases, the blue material tube pops off of the head during the auto load procedure in the F123 series. Future revisions of the print heads will address this, but a current work around is to print out the Pop fix STL and install it on the head. The STL file is attached and a picture of the part installed on a TPU head is below.

The STL titled pop_fix_with_air_cool_fix_clean.stl will work with any print head with a part number that ends in -0001 to -0005.

The STL 2022_NEW_HEAD_TUBE_FIX.STL will work with a head that has a part number that ends in -0006.

With the head in the machine, install the tube normally, then install the pop fix part onto the head to keep the tube secured.