I have installed only 4 devices my license subscription for 5 devices

I have purchased notion 360 for 5 devices, after installed 4 device when I tried to install 5th devices it show that I have installed all 5 devices

in 4th device it was not installed properly then I installed and installed. 

but my license has 5 devices. need support and help.

To free up an activation for your 5th device, log into your Norton Account at   www.my.norton.com .   Click on the user icon at the top right and click on Manage My Subscriptions. Then click on Manage Licenses and look through the list of devices to find any duplicates. If you find one, click on the trash can beside that item to remove it and free up the activation.