At the moment All Time Trials ranking is broken. Runs should be ranked by In-Game Time by default. On top of that rta ranking fetches completely different submissions which is clearly a bug or not desired feature.

it's weird but the only solution that works to see who's at the top rn is by clicking on in-game timer and it just reorganizes by in-game timing, but that doesn't solve the issue

As far as I'm aware, you can only set a primary sorting method for an entire game, not a category. It's clear that the primary sorting method for this game is RTA. Clicking "In Game Time" at the top of the All Time Trials leaderboard does solve the issue and allows you to see the board sorted as you requested. If All Time Trials is the only category with an IGT column, changing the primary sorting method to IGT should leave the other categories unaffected.

That doesn't sound very sustainable solution. Guess it's another feature of the website. Maybe I'll do a feature request or something of that's possible. There's no reason why a single category within a game shouldn't have a different primary sorting method, it's just not implemented yet.