To avoid confusion, it's best to enter chords in the first space of each measure (unless they are to be played later in the bar in which case a slash should be entered in spaces(s) as needed)
Please see the example in the middle of this chart: Bar Repeat Signs, Slash, N-C- - Example - Example
What is your intention in placing the repeat bracket at the start?
Is the form AB ("{:" is not needed) or AAB ( ":}" is needed at the end of the A-section)? )BOB