OK sorry for being stupid. The coins were on the old site at https://old.polycat.finance/

Polycat Finance was no longer paying stake rewards but I was able to unstake the coins. At first, the tokens did not appear on Metamask because the contract addresses were different from what they were before staking. I found the strange addresses and was able to swap the coins to Polygon (MATIC).

Staking stopped very soon after I was charged a 4% deposit fee so I lost some money. It was a hassle trying to make money on Polycat so I cannot recommend the platform to anybody.