I've never played the Arena before until the Seasonal event, and I've been enjoying it greatly! Enjoying the Seasonal Arena, that is... Since I've been having fun with the Seasonal Arena I wanted to try out the regular Arena, and I'm not finding it remotely as fun.

I don't get how the Rounds work! They'll just suddenly end without either team being knocked out, the Round counter(?) reaching zero, OR hitting the max turn limit. On several occasions the combat would end saying that the Turn Limit was hit when it wasn't even remotely close to 20 turns—not even breaching the double-digits. And what does "Combat halted" mean either??

I just don't understand it at all, and I can't find anything explaining this aspect of the Arena well...

Hello! Arena is so fun, I'm glad you're enjoying it. This is the official guide to Arena, but idk how much that will help since you're already in it!

The "normal" Arena is a PvP game, even though you typically just end up against bots. The rounds are a strict 1 minute to keep all players on task. Combat in LW is done by RNG, so the game rolls those dice and knows the outcome of each Arena battle instantly. The little creatures fighting each other on screen is just for our enjoyment! You can refresh really fast through Seasonal Arena turns if you didn't know already.

Round Counter reaching zero = 1 minute has passed, moving on
Max 20 rounds = a rule of Arena is that combat must be settled in 20 rounds (imagine if this was a real card game... 20+ rounds of dice rolls would take FOREVER!), so if the dice roll determines that no one has won within 20 rounds, you get that notice.
Combat Halted = I actually don't know, maybe just that just has something to do with syncing up players? 🤔