Uniswap getPair() does not deliver address(0)


I am currently testing the Uniswap function getPair()

mapping(address => mapping(address => address)) public override getPair;

and calling it from UI like this:

   const pairAddress = await this.state.factory.getPair(

For some reason, I am not always getting address(0) like in the documentation explained.

I deployed a fresh contract and cleared and removed the cache but getting always an address like "0x23De993d........" but I have not created anything