Is it no longer "Wladimir J. van der Laan" who signs the file?
According to this post
https://bitcointalk.org/index.php?topic=5360384.msg57956861#msg57956861It was signed by 0xb10c one of the developers of bitcoin core.
Actually, I'm also having an issue verifying the signature with Windows OS getting some errors when trying to verify it.
According to this
post, you need both SHA256SUMS and SHA256SUMS.asc but in my case import it to GPG tool only SHA256SUMS.asc I can import on GPG tool and I don't know how I will import the SHA256SUMS file on that tool to be able to verify the signature.
If you are looking on that two files then you can download them both here
https://bitcoincore.org/bin/bitcoin-core-22.0/