[Ethereum] How to sync liquidity pool on Pancakeswap with the BSC Testnet

I'm using this PCS clone on the testnet:

https://pancake.kiemtienonline360.com/#/swap

And I'm trying to understand how an elastic token works. I'm looking at Gravitoken (https://bscscan.com/address/0x1337ace33c2b3fc17d85f33dbd0ed73a896148b5#code) . So I deployed the token on the BSC TESTNET and set the Factory to: 0x6725F303b657a9451d8BA641348b6761A6CC7a17

​And the Router to: 0xD99D1c33F9fC3444f8101754aBC46c52416550D1

Now, I can add liquidity pool on this clone of PCS and I can buy/sell the token. The problem is that when I call the rebase function, and for example I remove half of the total supply, the balance on all the user wallets is halved, but the amount of tokens inside the liquidity pool doesn't change. I see the smart contract call LP.sync() on the rebase function. But it doesn't work. Is this a problem with the testnet/PCS clone or should I set up something in a different way?

I changed these lines:

IUniswapV2Router02 _uniswapV2Router = IUniswapV2Router02(0xD99D1c33F9fC3444f8101754aBC46c52416550D1);

uniswapV2PairAddress = IUniswapV2Factory(0x6725F303b657a9451d8BA641348b6761A6CC7a17);