how to simulate trading in Data Playback?

hello, i just tried the data playback feature but no idea how i may simulate the trades using the Signal. in real trading, when there is signal telling to buy / short, MC would submit the order and the corresponding markers would appear on the chart. So i expect it would do the same when playing back data with selected Signal.... but so far i can't manage to see this.

I can play back the data, but it order markers do not appear until i select "Recalculate Strategy" like the screen captured shown below.
So could someone help and tell me how to make the signal markers appear automatically?

Thanks for your attention and kindly help.

ok, i found the signal markers appear during Data Playback as long as i changed the following code in my strategy:

before Change:
buy 1 contract next bar Close stop
.... where Close is simply the close of data. So i suppose "Close" means the value in Close of the current bar.

After Change:
buy 1 contract next bar Price stop
... where Price is a specific value which is higher than the current bar Close. So when the price up and gets higher than this value, it would trigger to submit market order. Am i correct?

But no idea why the signal markers couldn't be shown before the change.