Once you've named your Branding Kit in your HubSpot settings, you cannot you edit the name. I ran into this with a client where they used a different brand name under their company and wanted to change it. I usually see some variation of "My brand kit" but they named it a specific brand. So if you've spelled something wrong or called it the wrong brand, we can't find a way to simply fix or rename.
Plus when you have your Brand Kit, you can't add another... but you can't delete your primary to replace it... so that's an infinite loop.
I did reach out to Support for help (Harsh was empathetic and supportive) and found out that while we couldn't change the name of the Branding Kit, HubSpot could. So we got it changed. But it would be nice to have this in our hands.