Hello Ben
If all the points have been configured correctly,you can just maintain the Default Account determination group for the Product Categories. System might need the default account determination for any differences postings such as Price or Exchange rate.
System would still post it to Fixed Asset if all the pre-requisites are fulfilled. You could just maintain the settings Otherwise you need to cancel the GSR and then mark the cancellation GSR as Irrelevant and try creating a new one.
Thanks
Parveen Kumar