It seems just a bit strange that your Ether that you say is showing on your metamask wallet set to Polygon network isn't showing in wallet.matic.network.  I double checked, any Ether sent from ethermine via their 'L2' option is shown in wallet.matic.network as Ether (PoS-WETH).

As you learned via the response from Guarda support, polygon wrapped Ether isn't just an ERC20 token, it's Ether that lives on the Polygon network, separate and distinct from Ethereum mainnet.

If you want to send Polygon wrapped Ether to any ERC20 wallet, you'll need to bridge that Ether over to the Ethereum mainnet.  There are a few ways to do this, I'd suggest familiarizing yourself with them by just doing a general google or youtube search for something like 'bridge to polygon.'  The way I use because I've found it easiest is actually linked right from the wallet.matic.network page, click on 'Move funds from Ethereum to Polygon' which will take you to the Polygon bridge.  You can move in either direction by clicking on the double arrow 'switch' icon.  If you view videos they will probably give an idea of the total cost to bridge, but I've said above it's been something like $40-50 for me in the past, this will be dependent on gas prices at the time you bridge.

You should read this thread carefully and then take time to research via google or youtube.  If you understand the concepts the questions will answer themselves.