[Question] Terastalize Pokémon on the map

[Sandslash Fan]

Hi all, just got Scarlet and having fun. I have been skipping most of the content and just running around filling the Pokedex. I capture all the overworld terastalize Pokémon that I encounter, but I've run into a Normal Toxapex twice in the same spot. Are the overworld terastalize Pokémon fixed in their tera type?

 

[Squirtkipfan01]

Id be willing to bet that its random each time, but i also am not 100% sure either. Ive went the whole game ignoring them lol

 

[Devalue]

Suggests fixed Tera types for overworld Terastal Pokemon on Serebii. Respawns daily.

 

[Sandslash Fan]

Suggests fixed Tera types for overworld Terastal Pokemon on Serebii. Respawns daily.

Thanks. I notice several on that list are the same tera type as their actual typing, which makes no sense. Such a waste.