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?

Hello Thunderbird Community, Please see attached. Here is another suspicious one for me. Is this a real or a fake update, please? Version: e1e6749e09 Thanks in advance.

I'm being offered what is clearly labeled Thunderbird 153.3.0esr. I see no sign of a version e1e6749e09. and Google seems to know nothing about it.

I'm not well-enough versed in Linux or Mint to diagnose this, except to wonder if you have added some other software source than the standard ones? There were some instructions posted recently about changing settings if you wanted to change from the ESR to Release channel, but I never bothered. Did you?

https://support.mozilla.org/en-US/kb/installing-thunderbird-linux#w_installing-thunderbird-manually-for-a-specific-release-channel-for-advanced-users