Since I had to re-insstall Thunderbird the default setting for all threads in my inbox on open/refresh is fully expanded. I'll collapse the uppermost threads, or even go to "'View' > 'Threads' > 'Collapse all threads' ", and if I change to another folder, when I return to main inbox all threads are expanded again. If there's a quick trick to change the default setting that would be great, thank you! (I have read this solution before: https://support.mozilla.org/en-US/questions/1171612)