XF4 won't update

XF4 recognized by the Mod Dwarf in control chain.
Begin update by disconnecting.
Holding switch one down I connect XF4 ussb to Mod Dwarf.
Nothing happens.

Connected XF4 usb to Mod Duo.
Nothing happens.
Connected XF4 to computer.
It doesn’t mount as drive so can’t do manual update.

Tried this with two different usb cables. no change

Help!

Do you follow the wiki?

https://wiki.mod.audio/wiki/Control_Chain_Releases