Before the main-print starting two LONG lines are extruding. Why so much filament for this? Before the update the line was only one and much shorter, like 10 cm, but now with the new update the line now are two and 24 cm long.
Is this because of the MMU2S part? Extruding to get the correct color?
(Otherwise my obsveration is that the filament wont struck to the extruder as before when doing the first pre-line, now with two lines the filament strucks direct to the heatbed)
Have a look in Slic3r Printer settings - Custom G-code - Start G-code
Scroll down to the bottom where you should see this:
G1 X60.0 E9.0 F1000.0 ; intro line
G1 X100.0 E12.5 F1000.0 ; intro line
The X60.0 and X100.0 are your line lengths and the E9.0 and E12.5 are the extrusion amount with the F1000.0 the speed.
Check yours, and adjust to the above if not using an mmu.