Download fails on all files except very small ones

[MichaelInParis]

I am using FileZilla 3.30.0 in order to connect from my Windows 10 Home 64 bit PC to my office server (Windows 2003 server) through a VPN internet connection.

I am able to upload (from my PC to the server) files of any size, but cannot download files larger than a couple of Kbytes: in the example below, the transfer fails after 2,920 bytes, restarts the loading (where it stopped, I imagine), fails again after the subsequent 2,920 bytes), and so on, until in the end it aborts the connection before having managed to load the whole file.

I hadn't used this connection in order to download contents for quite a while, but am pretty sure it worked well with my previous home PC (which was running Windows 7). This is a new machine, to which I copied the FileZilla parameters.

[MichaelInParis]

Screenshot of start and end of failed transfer

[Tim Kosse]

A firewall or another networking component is actively sabotaging the connection.