Since I have imported my Vault from Bitwarden, all of the Credential Names in my vault have ".com" at the end.
When creating an Alias through Proton Pass, the Prefix defaults to the Whole Name of the Credential, not the Domain.
As a result, the following Alias will be formatted like:
"google.com.abc123@simplelogin.com"
instead of:
"google.abc123@simplelogin.com"

Because of this, there are many websites that will refuse to accept these Aliases due to its format.
There is no way of changing the Default Prefix in Proton Pass, so every time I have to create an Alias, I have to manually edit it each Alias through Advanced Options.

With that being said, please consider adding in an option to change the Prefix Defaults when creating Aliases, I'd rather not go though my 800+ Item Vault and remove ".com" from each and every one manually.