Cant access PRO features

I’ve had nothing but problems with this plugin from the very start. First of all, when the plugin was purchased initially, it forced us to buy 4 licenses when all we needed was one, but whatever. Now for whatever reason, even though the website says we have 2 of the 4 licenses remaining, it wouldn’t let me download the plugin because the license was apparently expired, even though two of which were never activated, but whatever. So, we just purchased a new license, downloaded the plugin, installed and network activated it (on a multisite install BTW). However, it never asks me to enter a license key, and when I go to the settings to access the PRO features, they are not accessible. There’s just a button that says “Upgrade to PRO”, which upon clicking, I get sent to an error page that says “Sorry, you are not allowed to access this page.” I have tried disabling all plugins on the site and also switching to the default WordPress theme, but none of which seems to make any difference. I’ve even tried installing previous versions of the plugin, but the results were still the same. So, what’s the deal here? Why can’t I access the features that were paid for?