Have you fastened the lobster on a light and pulled hard on the lanyard?
I do this every time with new lanyards and sometimes something brakes….
I use custom made Ti threaded needles….
Easy to make. By cheap Ti tent peg and find some one nice to machine on a lathe.
Very impressive, the fid as well as the knotwork. 
Very nice Conquistador bracelet , Essexman !
I am currently experimenting with that weave as well .
Well done .