I have an Avast Ultimate subscription for 10 devices working on my Windows PCs and Mac but it doesn't work on the mobile VPN app. When I enter the activation code it says "hmm that didn't look right. check the activation code and try again.". When I try pairing using my windows pc it says "We cant pair your device it seems you've got a single-platform subscription and you're trying to activate it on a different platform.". On the subscription, it said you can use it on all platforms.