What shall I do if the main is moving forward when furling?

The main is powered. Ease the main sheet or point higher.
The outboard end of the boom is too low. See about correct furling angle and the use of kicker in the operating guide.
The main should be pulled down, not dropped. Keep a sufficient resistance on the main halyard by hand and the FurlerBoom
main halyard control block. The brake force on the control block can be adjusted on the center bolt with a 17 key.