Issue with opening an ETH/DAI pool on Rinkeby

Hi there.

I was trying to create an ETH/DAI pool on Rinkeby testnet and couldn’t do this. The first transaction with approving DAI tokens went well but the second one didn’t even occur (I hit the “Create Pool & Supply” button and nothing had happened). In the console logs on the website I saw an error “MetaMask - RPC Error: execution reverted: UniswapV2Router: INSUFFICIENT_B_AMOUNT” that is really weird as I have 700 DAI in my wallet (and I was able to successfully send an approval transaction that confirms that I actually have 100 DAI).

Do you know how to open pool / provide a liquidity on Ropsten? Or just any pair of tokens on any test network, so that I could get testnet LP tokens?