CPU Spike lag with Webgl build

Hello,

I tried to create a pooling system for my project. This system spawns at the start of the game more than 500 coins. The scene they are spawned only has a vase in which they are going to be dropped in with Physics.

First, they all are disabled and with a counter, they will be activated one by one.
I didn't have any troubles on my pc, but I did have problems with WebGL.
Activating the coins one by one didn't cause the problem, but if I activate too many within a period, then a lag spike occurs. This happens between 5-6 seconds.

 

A picture of the profiler

 

I did notice that instancing does not work after switching to WebGL.