When I open Todoist, it shows me search results for 'all'. Why? I didn't configure it that way.
Please go to the Settings -> Account and let me know what Start Page do you have set up there and if changing it to something else and back solves this issue.
Also, are you accessing Todoist directly through https://todoist.com or do you have a bookmark which may point to an URL containing the search for "all"?
I had "custom query" there. It seems changing that solved the problem.
I registered for Todoist in 2008, then went away for years and returned recently after I noticed how much Todoist had improved. That custom query was maybe from those times.