I've been using Thunderbird on my Win10 PC for many many years, (and donated to Mozilla) and all has been fine till mid December. Emails still work fine on my Android phone and tablet using the Gmail app for my main Gmail email address and K9 app for an old email address, but on my PC using Thunderbird they both suddenly stopped around mid December. I can't give an exact date as I'm now disabled so only use my PC every fortnight or so just to keep everything up to date. Thunderbird is using the server settings recommended by Melbpc group and they haven't changed for years. I also use Nord VPN which recently underwent what seemed a major upgrade so I turned that off - no difference. I then tried manually instigating a download of my primary Gmail email on the pc using Thunderbird and watched as it said "connecting to  imap.gmail.com", then "connected to imap.gmail.com" but then nothing happened. Everything is totally up to date - Win 10, Thunderbird etc.. Can anybody suggest what the cause might be please?