There is an issue with the existing reference implementation when experimenting with the new reduced-signature size SPHINCS+ parameter sets due to the fact that some of the new parameter sets utilize large subtree sizes (i.e., > 16) that result in the address.c::set_keypair_addr() function not setting all of the necessary bits as it only copies over the first two bytes.
In general, you may want to modify all ADDR-handling functions to ensure they copy over, or set, all of the bytes of each of the ADDR fields to ensure this doesn't happen.
There is an issue with the existing reference implementation when experimenting with the new reduced-signature size SPHINCS+ parameter sets due to the fact that some of the new parameter sets utilize large subtree sizes (i.e., > 16) that result in the address.c::set_keypair_addr() function not setting all of the necessary bits as it only copies over the first two bytes.
In general, you may want to modify all ADDR-handling functions to ensure they copy over, or set, all of the bytes of each of the ADDR fields to ensure this doesn't happen.