When one of these gets focus all text is selected, as expected.

Expectation is

• pressing backspace should stop selecting and clear the entire contents like a TextFiled would - instead it stops selecting and the cursor is between the last two chars (e.g. for 08:52:40, the cursor is between the 4 and 0).
• pressing right arrow should stop selecting and the cursor would be at the very end. - instead it stops selecting and the cursor is between the last two chars (e.g. for 08:52:40, the cursor is between the 4 and 0). Pressing 3 should make it 08:52:43, which it does, but the cursor stays between the 4 and 3. Thus the insertion point is in the right place but not the cursor.

Etc...