I'll cut to the chase and give you an example on how they're broken.
Turn 1:
I use Spikes

Turn 2:
Opponent switches out
The game states the opponent is affected by the Spikes, however the opponent did not take damage
Examples:
https://media.discordapp.net/attachment ... height=701
https://media.discordapp.net/attachment ... height=701

Turn 3:
The Opponent switches out again
The Opponent is finally affected by the hazards

TLDR; Hazard moves take an extra turn to take effect
This is the case both if the NPC uses these moves, and if the Player uses these moves.

Hi, I have tested your report and can confirm there to be issues related to hazard damage. I could not reproduce it every time but it did happen very frequently and it isn't just attached to Turn 2, happens in other turns as well. There's also some visual glitches such as a poisoned Pokémon sometimes not having the poisoned icon.
Here are a few samples of my own too:
https://gyazo.com/a44577ad6b0fc57e25769e62c96f7fef
https://gyazo.com/a63a7cdd92104d2d96ec208ac1e1fad5
https://gyazo.com/abec281e2cd481b44f30bc8b03c6b376
https://gyazo.com/15e8b1cf2c59624908c88a3404ad9fde
https://gyazo.com/d568e7456ad1710c27fcd0bfad400d0d
https://gyazo.com/7dc9a7b2ad6e535bf6e7e52d881ba944

Will be moved to internal soon.
Thanks for your report!

Thank you; this issue has been moved to internal.