FTP Upload

I moved over to T-Mobile Home Internet about 2 months ago.  I use winscp, filezilla and terminal regularly in maintenance of several web sites.  WinSCP and filezilla had worked fine for me until this weekend when directory listing mostly appeared to time out and any file edit/saves (say via winscp) failed as well. This had been working without issue, so something in my 5G coverage has to have changed.  Very frustrating! I found Guardian61's post above and using a VPN resolved the issue for me, though likely for a different reason (NAT/Port Map/IP duration). FTP is a TCP based service exclusively. There is no UDP component to FTP.

I'm still wondering what happened and why and have a ticket open with T-Mobile.  As a test to see if possibly something had changed in the site hosting environment or on my laptop I hopped over to a coffee shop and exercised both filezilla and winscp using my existing configurations.  The ftp services worked as expected (without VPN) and indicate no change in the endpoints, that leaves the network.