Please don't shoot the messenger as this may sound crazy to some, but you should really consider modifying your speaker placement to optimize for each cable before doing your listening comparisons.
A couple of years ago, we did a speaker cable shootout between two well respected high end cable brands, with a highly regarded regarded setup professional present to optimize the speaker set up for each cable.
The results were remarkable: There was a significant difference in how the system sounded using cable 2 in the speaker position optimized for cable 1, than how the system sounded using cable 2 in the speaker position optimized for cable 2. Using cable 2 in the speaker position optimized for cable 2 sounded so much better than using cable 2 in the speaker position optimized for cable 1. And vice-a-versa.
Our preferences would have been very different if we had left the speaker positions unchanged between switching cables. Caveat Emptor.
I hope you also went through all the permutations and combinations of power cords, fuses, interconnects, and sources. Otherwise, your optima are just local optima.
Seriously though .., I suspect that your room had/has unresolved issues. The tonal balances of the speaker cables were probably different enough that different room and reflection modes were exacerbated by one compared to the other.
I do think that changing a component to mitigate a flaw in some other component is a misguided approach. Once you’ve got your room right and your speakers are properly located in that room, the goal in every bit of gear should be neutrality. Of course getting the room right is sometimes a difficult proposition.
An awful lot of audiophile discussions are a quest for sound rather than a quest for music. We make it very hard for normal people to buy in, even at the sane levels of a $20k system. Our OCD behavior spreads waves of fear and anxiety to naive readers.
We all respond to audio stimuli differently (Equal Loudness Curves are averages, not exact representations for every human). It is not a surprise that we do not all agree on “What’s Best?”. Or even on “What’s Rational?”.