You are so right. I speak from recent experience:
I had an open lower (bottom) back seam. It was about 12''
from the right side (top view down) of the peg, upwards.
I blithely continued playing it, hoping to get it done Some Other Time (great tune )
Then about a month or two ago, I heard a great thump, crash, rattle! The bottom of the bass caved in, the bridge slipped out and the strings slapped on the top.
My hind-sight advce: Get 'er glued. I'm now reduced to playing my old fender-- just to keep my hands in shape.
My first thought was that the cable you sold me broke or slipped.