Help needed: issues with moving from Gmail to ProtonMail

[cazboy]

I'm running Windows 10.

I'm trying to understand a couple of things about how ProtonMail works. I've got an email set up with them, and I've managed to import all my "Gmail emails" into my new ProtonMail address. I want to file all my newly-imported emails into folders, like I had in Gmail.

But ProtonMail seems to have what they call "labels" associated with each email.

When I try to make a folder in ProtonMail to put the email into, a popup message says "There is already a Label with that name". Yeah, I know there's a label with that name, I'm trying to make a folder - not a label!

Why can't I make a folder in ProtonMail with the same name that I had in Gmail? All I'm trying to do is replicate my "filing system" that I was used to in Gmail.

Thanks in advance.