The problem is that when Thunderbird is running during normal operation and I leave the computer for at least 30 minutes, it stops downloading new messages. After closing and restarting the program, new messages are downloaded. On a mobile device with the same email account, messages arrive all the time. I have Thunderbird version 115.4.1 installed on Windows 11. The email account is configured with the IMAP protocol.

1. The firewall and antivirus program have been disabled 2. Windows patches have been installed 3. Windows power saving options have been disabled 4. Windows device drivers have been updated to the latest versions 5. In the TB configuration, ports were changed and SSL was enabled/disabled 6. The inbox folder has been rebuilt several times