Thunderbird will not update to new version 9d1ba1e8a1 on Linux Mint.

Strictly speaking, this would be a Mint problem, not a Thunderbird one. And your screen shot looks odd to me. As far as I know, there is no version "9d1ba1e8a1". Did you install this from Mint's own package manager or from elsewhere?

I just fired up my Mint 22.3 machine and I'm being offered a Thunderbird update that's clearly labeled as 140.12.0esr. I wonder if it would help if you refreshed your software sources cache by going to <Update Manager | Edit | Software Sources | Official Repositories> and let it scan for a new mirror?