Hi @Dom
On ONE machine, this shortcut applies a different tag.
If the shortcut applies a different one tag, I suggest you go to Tags list, please make sure the To Do tag is shown as the first one.
If it is already the first one with (Ctrl + 1) shown, please find the tag that accessed via Ctrl +1 actually, click "Remove". Then continue to remove To Do tag, and then create these tags back for a check. (Please note, you need to ensure the To Do tag is the first one.)
Besides, please make sure the shortcut of Ctrl +1 is not occupied, such as the shortcut key for graphics card settings, shortcut key for input method language switching, etc.
If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.