Hi @josepp , welcome to the MetaMask community,
The issue is either related to the Polygon RPC you are using or the network/IP. Changing the RPC may resolve the issue. You can change it using the following link. Please remove the 2 spaces I inserted in the link.
https:// chainlist. org/
To see the list of the RPCs, click on the small arrow at the bottom of the Polygon network box. Then add an appropriate one to your wallet.
For more information, refer to the following article.