It looks like high level Pokemon won't obey your commands even if you are their original trainer now. Does it work by the Pokemon's current level relative to how many gym badges you have, or is it what level the Pokemon was when you caught it?
Starting in Legends: Arceus, this applies even to non-outsider Pokémon, but is based on met level instead of current level. In Generation IX non-outsider Pokémon are treated as outsider Pokémon for this purpose if they have ever been traded, even if they are traded back to their Original Trainer.
https://bulbapedia.bulbagarden.net/wiki/Obedience
Honestly I could've sworn it was always like this but apparently yeah this a recent thing. Basically if it's a Pokemon you yourself caught then it depends on the level you caught it. I can confirm from experience, I caught a high-level Slacking myself and it did not obey me until I got more badges while similarly leveled Pokemon I caught earlier still did.
In addition, regardless of the original trainer any Pokemon traded even once will now also be treated like outsider Pokemon.
Here are the levels and badge number requirements for Scarlet and Violet:
1 Gym Badge Lv. 25 2 Gym Badges Lv. 30 3 Gym Badges Lv. 35 4 Gym Badges Lv. 40 5 Gym Badges Lv. 45 6 Gym Badges Lv. 50 7 Gym Badges Lv. 55 8 Gym Badges Pokémon of All Levels
Also,
Pokémon that you've caught below the Level limit will always listen to you, even after they've been raised to exceed the level limit. As an example, even if you do not have a badge, a Pokémon you've caught below Lv. 25 will always listen to you, even after they exceed Level 25. However, if you try to use Pokémon that were caught beyond the level limit, they are more likely to disobey you. Make sure that the Pokémon you catch do not exceed the maximum level allowed by your current number of badges. If you insist on catching them, you'll have to earn more badges before they obey.
Pokémon that you've caught below the Level limit will always listen to you, even after they've been raised to exceed the level limit. As an example, even if you do not have a badge, a Pokémon you've caught below Lv. 25 will always listen to you, even after they exceed Level 25.
However, if you try to use Pokémon that were caught beyond the level limit, they are more likely to disobey you. Make sure that the Pokémon you catch do not exceed the maximum level allowed by your current number of badges. If you insist on catching them, you'll have to earn more badges before they obey.
Source