We are using FTP to download a file from a client's FTP to our server, we're using 8.5.5 PRO.
The file that VisualCron downloads shows it was last updated on Dec 2 (Properties).
If I download the same file using FileZilla, the file shows it was last updated on Dec 15 (Properties).
I even tried deleting the file from their FTP and loading the latest one and same result.

Why would VC pull an older file when there's only one file on this FTP with the mask we are looking for?
Is something caching somewhere?

I strongly recommend updating. Not only because of fixed issues but also for security patches in general and debugging. Newer builds will also be better at debugging this.

Normally, you should be able to use the Test tab to see which files should be downloaded. If the result is empty then there is something about the filter you use.

---

Here's how we resolved this:

We are not getting the latest file using FTP protocol, however if we use SFTP protocol we get the latest files. Our provider confirmed they use SFTP for upload as well. The only way to identify this is to download the same file using FileZilla (SFTP protocol), then download the same file using the VisualCron task, then go to File > Properties and compare the dates.