One of the users unable to see 'Other Work' when they try to 'Add Tasks - Select Task' to the Timesheet and I confirmed that she was using the correct 'Select Tasks' option and not 'Assigned Tasks'
I also confirmed that she did not have any filters set at all, and the quick search was also blank.
User was using Google Chrome as browser, and we cleared the browser's cache and cookies, closed all instances of Chrome, and tried again to no avail.
As an Admin, I opened her Timesheet and had no problem adding the 'Other Work' rows that she needed and she was able to book time.
Google Chrome version.
Release : 16.0.1
Component : Clarity Time Management
User had very old Chrome version 80, once updated to the current version this resolved the issue.