Problems with RNG?

[Rickvs]

SOLVED
Testing, reproducing and fixing RNG-related bugs has always been one of the most tedious activities in game development. You're forced to constantly "guess" whether your diceroll mechanic is broken or you're just really, really unlucky.

Anyway, my currrent problem is that I've set up normal wild encounters in my map but the spawn chances seem really off.

ELECTRIKE is set to a spawn chance of 4%.
Except that everytime I load my game and trigger a wild encounter in tall grass, 9/10 times I'll run into ELECTRIKE. Sometimes I'll run into another Pokémon, but it mostly seems to be that one 4% chance Pokémon. I've tried replacing ELECTRIKE with various different creatures (and cheching their "Rareness" value in pokemon.txt).
No luck.

My game is made in Pokémon Essentials v16.2, modded with the Elite Battle System.
I've duplicated the map and relevant section in encounters.txt over to a new, unmodded version of Pokémon Essentials and the issue remained.

Testing session recorded just now (unmodded, new game):

Spoiler:

In order of encountering:
1. ELECTRIKE
2. ELECTRIKE
3. POOCHYENA
4. ELECTRIKE
5. ELECTRIKE
6. ELECTRIKE
7. SHUCKLE
8. SHUCKLE
9. ELECTRIKE
10. ELECTRIKE

Obviously I've waited a while and done several testing session to make sure this can't simply be shrugged off as a case of bad luck. It's becoming a serious issue for me.

 

[Maruno]

I don't suppose the Pok?mon at the front of your party has the ability Static, does it? The ability which forces Electric-type wild Pok?mon to be more common?

Incidentally, the "Rareness" value in pokemon.txt is how difficult a species is to capture. It has nothing to do with encounter rates. It's a poorly named value.

 

[Rickvs]

I don't suppose the Pokémon at the front of your party has the ability Static, does it? The ability which forces Electric-type wild Pokémon to be more common?

...goddamnit.
I used the same debug Pokémon in every test session... with Pikachu in the lead. Fucking hell I'm an idiot.
Thank you so much!