Susan Ridgeon I have the same problem.
For some tasks (not all tasks), sometimes (not at all times), the history for tasks does not load. Erratic behaviour.
I've reproduced the problem in Chrome, Chrome Incognito (to remove extensions that may be interfering), and Opera browser with no extension.
Notice the "loading" message on top left. Also highlighted in yellow the area where task history should be (e.g. creation date, etc.).