Hi,
Thanks all for replies on this. I've done a bit more digging - it only occurs on tasks that have an end date that is now in the past where the task isn't marked as complete.
So for example - if I want to record a task as having started on 15/11/2024 (UK dating style) it allows me to enter the start date. But if I want to record the proposed finish date as 16/11/2024, or any date prior to today's date, it won't show that date. This means that I'm not able to clearly see activities that have missed their deadlines.

As you can see from the image - all tasks/milestones with an end date in the future show the date - whereas any with end dates in the past (these are all milestones) don't show it if the task is incomplete. They do show the date if the task is marked as complete though.
Tin - I use Edge as my default browser, as that's what our work laptops are configured for. I've done a quick check on Google Chrome, and the same error seems to be present. But the other people viewing this plan will use Edge as a default, as that's our organisational approach.
Any help to resolve this gratefully appreciated!
Thanks,
Thomas