Where is a good spot for Pokemon hunting on Penang Island ?

Last week, I cleaned up my Pokémons and in the process, I transferred out many Pikachus with mediocre CP and IV. After that I realized that I don't have any Pikachu with the Christmas hat anymore, and know that it must be a bug in the game. My wife also doesn't have Pikachu with Christmas hat anymore, and I told her not to do anything about it yet.

Today I check and found the following update note from Niantic:
Resolved a bug which caused Pikachu hats to disappear from the in-game model and icon.

Damed it, have to wait for next Christmas to get them back.

I think they set time. They set theirs hp time fast few min or hours before put in their pokemon. Any one try attack will hit error. This happen to me all the time in Pg.
* use same pokemon to attack them. If D9 use D9, if Bc use Bc. U won't get error.

Some uncles did mention about arses deliberately preventing takeovers but they couldnt explain how. Thanks.
I did use the exact same attackers but keep error and stuck in battle even after timer ended.