Firstly I use the following:

- HTC One
- Dell laptop running Windows 8
- iPad 2

When I input a task into Outlook it appears in "Tasks" in my HTC One and also "reminders" in my iPad.

However, when I insert a task in my HTC One, it appears in "Tasks" on the HTC One and in Outlook but not my iPad.

Similarly when I insert a task via my iPad it appears in both the iPad and Outlook tasks but not my HTC One.

Any idea how I can resolve this please?