In addition to the advice everyone else has given, you said you used 1/16" shock cord? It looks like 1/8" in the last photo, but I could be wrong on my ID there.
If you did use 1/16", that may be a little too narrow and not offer enough "pull" against the cord locks. I had issues with that with my first PLUQ attempt, and it definitely made a difference when I shifted over to 1/8".
Hope it helps!