I did try with a display, but I just realized I hadn’t wired the mode via when I did. They all read 74.5 when checked against groundHave you tried actually using it with a display? My best guess is that while the resistances between those lines and ground is small enough to make your continuity meter trigger, it may be fine as is. Check the actual resistances on each line to make sure they aren't 0 or something. Your soldering looks fine, I don't see too much exposed wire on the ends that could be shorting.
I forced a battery clip through the outer coating into one of the connections and it caught fire lol. everything works fine thoughUh oh, did you you put a battery in the wrong way?