i am having the same problem.
When it is writing the ROM onto the cart it doesn’t show any progress on the GBA screen, Write # and End # remain at “0” throughout the whole process - meanwhile the computer does seem like it is writing.
my f2a linker is parallel.
This seems to be the only thing...
although i ended up accidentally changing my nand with no way of going back bc i didn't know you needed a gamecube controller to restore it (i have a wii minus/1.1, which doesn't have gamecube controller support)
and if i find the sd card i have my NAND backed up on, i can not only restore the NAND if i solder the right part in, but i can also put my NAND on dolphin, then i can play dolphin online, like PMEX Remix or MKWii Riibalanced