Found wallet seed, but it is empty

Hi,

In 2022, a family member sadly passed away unexpectedly. We knew he was into Crypto and we actually found 2 wallet's seed. One was hidden behind a photo frame (inside the frame, so we had to remove the picture in order to find it). Another was in a black notebook in a random page.

I recovered the 2 wallets successfully but, I can't see anything on them. I assumming I need to be in the right network to be able to check? I checked for BTC, ETH, BSC, etc but nothing. No transactions either as I would appreciate if they were emptied but no, so no history which leads me to believe, I don't know what to look for...

Any advise?

UPDATE 2: I found an old email from 2018. He wanted to send 1 litecoin to a family member through me:

"Just to note i have 20 different crypto currencies.

Bitcoin, litecoin, monero, neo, maybe you want me to transfer it using one of these options? Ofcourse it convienient if you have a card setup for quick widravals"

What should I be looking on the hard drives? Unfortunately the partner took his personal computer when he passed so no real access to that. I managed to recover access to 3 different email accounts but no luck with anything related to crypto. There is 1 other account that I will need to gain access to, hoping that will be the one.