Yeah, the reason sources differ is because everyone kind of builds their own tarot "language" over time. There are common threads and basic keywords for each card, but at the end of the day you're supposed to shape meanings that make sense to you.
Personally, I don't read reversals anymore, but when I did, I treated them as frustration, blocks, or the "opposite" of the upright energy.
For me, all the Aces are like a wellspring — the raw source of their suit. So the Ace of Wands upright is spark, energy, inspiration, new opportunities, passion, willpower. Flip that around, and you get things like blocked energy, hesitation, lack of motivation, or a project that stalls before it can get going.
Some people also read it as fatigue, apathy, or aimlessness — basically that spark trying to come through, but getting stuck.