Hello,
Yes, Fences v5 is a new upgrade version so it will need new key to activate it. If you review this thread : https://forums.stardock.com/524050. You will notice mention in there that any purchase after 15th October, 2023 will get complementary upgrade to it. Please check your email box or your Stardock account page if Fences 5 already listed in there.
If nothing appear there. Please raise support ticket using the link below, use the "Ask a Question" option. Include all information details. Remember to record down the ticket number for future reference if needed. Do not raise multiple ticket, that will make your ticket back to the end of the line. Send once and wait. Ticket will be answer by the order they send in.
https://stardock.atlassian.net/servicedesk/customer/portal/4/group/13
Do know that Stardock on Holidays now. So Support might be a little late. We appreciate your patience.
Thanks
Basj,
Stardock Community Assistant