Hey Ive encountered a few themed sylesties and whenever i try and capture them, it keeps saying that the snares can only be used on wild pets, even When Im using them on wild themes. Is anyone else having this problem?

Yes i did, i think the mojo pets are not seen as wild. I didn't try catching another themmed ( mostly because i only ran into draely and morkko afterward.) XD

It was probably Mojo pets, found during stage 2 of the Zone Event (collect Mojo) up until the Master of Nightmares (stage 3) starts. The Mojo pets appear with "Rare Enemy", and have appearance of either Zombified or past Mojo event pets* (eg. Devious Bulbori or Will O' Wisp Lunemara), but they aren't considered as 'pets/wild sylesti'

What they are there for is to be Mojo'd (hence the name "Mojo [species name]")- you get Mojo collectors as drops from the occultists that can spawn from the start of Stage 1 through to the start of stage 3, then, when you run across a Mojo pet, you weaken it, go to Traps, and select the Mojo Collector.

This gets points for the Mojo round, and has a very small chance of giving you a theme egg (I assume matching the Theme base of the pet you mojo'ed, so a Mojo kelpari with the Zombified Theme Colour Palette gives a Zombified Kelpari egg) for a successful mojo.

You can find and trap regular theme pets per usual, though.

(*Mojo events working a lot differently during previous Fall Fests as compared to this one)