Unable to set stop loss on the chart

I have one click trading selected in Tools/Options. I’ve accepted the agreement. The stop loss field in the New Order dialog is at its default 0.000 along with Instant Execution . Yet sometimes on the chart I’m able to drag to the stop loss level that I want and other times not. An unpleasant sound is heard and the red stop loss line disappears. I try other levels for the stop loss both closer and farther from the entry price. No luck. For some trades it works, for other trades not. Any ideas?

New info: The above was an attempt to set the stop loss on a 15 minute chart. But on the same pair it can be set on the 1 hour chart without difficulty. Why is that?

Solution? It looks like I’ve misread the pips of the stop loss on the 15 min chart. Apparently I did not take the increased scale of the 15 min chart over the 1 hour chart into account and was reading “12” instead of the correct 1.2 pips.

Only issues I do see with setting stop-loss is if I try to drag or set the level too close to current price, or try to set it the wring side of the entry price. The colour of the SL line goes grey and fails to hold when I release the mouse button: my platform makes no sound when setting/moving an order like this fails, whereas a successful placement makes a sharp click.

Don’t forget, you can’t place a SL above a long or below a short…

Thanks for taking time to reply but your suggestions are not the source of my problem.