Looks like it was user error on my part! I was hitting 'Save' instead of 'Save and update Content' 🤦‍♂️ Thanks for the help!

@Tigran Shahnazaryan Thanks for the reply! I had tried that, but when I deploy the custom portlet I selected, it doesn't seem to carry over to the role I selected. Instead, the user in that role would have to set up their custom portlet within the Center Tab. Am I missing something, or is this just how it works?