Recently, I have experienced an erroneous browser launch, simply by clicking on the title of the message in the list pane. This problem seems to occur when clicking on emails from a particular UK supermarket (tesco.com) and the web page opened has a long and complicated URL, but the page contains only a single pixel which shows up as a white dot on a black background. Obviously, it is likely that there is something strange about that source, but the problem doesn't occur if I click on the same email in a different email client (in this case Evolution). I have tried various Settings as advised by web searches and also the solutions suggested in Thunderbird Help (Troubleshooting Mode and Troubleshooting Information). I am running Thunderbird 140.5.0esr (64-bit) on Kubuntu Linux 24.04.