Why are the links not created?

I just noticed an important detail but I don’t know what it is, when creating links using a premium list.
Step to detail:
When I start a campaign using the premium list, GSA SER begins to create links quickly at the beginning, in seconds I have been able to observe that the VPM: 0.50 max (in my case)
After about 6 hours I have managed to get a maximum of 120 links, and the VPM drops to 0. Without filters, totally without filters so that many links can be created.
But that’s not the problem …
After 1-2 days GSA SER still does not create links, creates 1 to 3 links per day, USING THE PREMIUM LIST, Without filters!
I’m beginning to doubt that it can be the lists.
Because I say this …
Currently I have a paused campaign that was done with GSA SER + Scrapebox to harvest and create links. This campaign from the first day has created links without stopping, to such an extent that I have used the filter to pause the campaign every 120 verified links, which is great.
So, drawing preliminary conclusions you could say that the VPS, proxies, emails cannot be the problem.
I do not know exactly if they are the lists or some synchronization configuration is incorrect.
People who use premium lists, could you give me some advice or comment, I would greatly appreciate it.