Dragonite resists electric?

I've been noticing this as well, including with several others I can't think of at the moment ( I may be wrong, it might just be dragonite). I thought this had been present since the beginning of the game's release, but again I'm not sure. I've figured that it is meant to be similar to how in gen 1, the first type would carry priority over the second type, causing odd dual type situations like this. It could very well be a bug though, and I'm curious to anyone else's experiences
NessOurHero

Weakness = Damage x 7/5
Resistance = Damage x 5/7
7/5 x 5/7 = 1

Theoretically weakness and resistance should cancel out completely. ... except Niantic rounds the multipliers to the third decimal place.

Weakness = Damage x 1.4
Resistance = Damage x .714
1.4 x .714 = .9996

The "Super effective" and "Not very effective" text is apparently just looking for any multiplier greater than or less than 1. By the end of the damage calculation, the final result is rounded down and the difference between 5/7 and .714 is probably fairly minimal.

I always use my 100 IV lvl 38 Jynx against nite. Frost breath beat it before charge move. Electric against vapo and Gyarados. Niantic calculations are very unaccurate. Same as attack damage calculation.

1) Nice spot!
2) You can call it a "bug" because technically it deals neutral damge. In fact it's just a rounding error.
3) For detailed numbers regarding why you see "not very effective", you can find it in this post: https://www.reddit.com/r/TheSilphRoad/comments/6q8l2z/why_does_dragonite_resist_electric_attacks/