I have (supposedly) 2 pages of threads I have subscribed to, totaling 53. I see 6 on page one, and page 2 says I haven't subscribed to any posts. Internet Explorer and Chrome exhibit the same issue.
Does this link show them https://forums.stardock.com/subscriptions
it does on mine Win 10 v1803
The same issue exists.
I send a note to support for you for help , Stay Tuned Jim