Update is not update

I'm unsing portableapp since early 2000.
In the last period the update process is not working correctly.
If I activate the update check, I get a list of apps to be updated.
If I check one or more apps and click on proceed, the update process starts and ends with positive result.
But it's not true.
If I activate again the update check, I get again the previous list of apps to be updated.
What could be the reason and how to solve it ?

Thx