What I'm offering isn't a solution, as Microsoft doesn't allow rules to be used in the spam folder.
But at least you can more easily identify spam from gostarmedia by changing its appearance.
I was surprised that another setting, "Conditional Formatting," affects messages in the spam folder.
So you can create conditional formatting rules to change the color of problematic emails.
I'm wondering why Microsoft has blocked email rules from working in the spam folder, but still allows conditional formatting rules.
Outlook can clearly detect emails from gostarmedia, but for some strange reason, you're not allowed to use detection in rules to delete them.

Create the Conditional Formatting as you like. Use gostarmedia, gostarmedia.com, etc. and choose the color.

Now It's easier for me to search and delete gostarmedia messages.