Need explanation on Sell Stop Order

 
I’m new to trading and not sure if I understand correctly how Sell Stop orders work.

The stop order I placed started at the my set price, but exited way too early and not at my SL. I don’t know why it happened and if I did anything wrong. 

Here are the details:
I placed a pending order to sell Silver, as I expected its price to drop. 
The market price when I placed the order was around 26.9. (7th Sep 1am)
I set to sell stop at 26.44, SL at 27.7 and TP 23.
The order was executed to sell 26.44 (08 Sep 14:42)
My position was unexpectedly closed by buying at 26.581. (08 Sep 15:24)

Can anyone explain to me why the position was closed like that? 

Thank you in advance! 

PS: As I tried to look into the order history, I couldn’t see the SL and TP I set. Everything is just 0.000. 
 

Looks like something has been messing up your trade, maybe from a remote terminal.

The SL and TP values as set by you have to appear in the history (I know this broker), but since they are missing it's likely that something got hold of that trade.

Check for signal subscriptions or EAs that may have been set up for your account and read the log files.

 
lippmaje:

Looks like something has been messing up your trade, maybe from a remote terminal.

The SL and TP values as set by you have to appear in the history (I know this broker), but since they are missing it's likely that something got hold of that trade.

Check for signal subscriptions or EAs that may have been set up for your account and read the log files.

Thank you very much for your reply. I am not aware of any signal subscriptions or EA that may have been set up.

I’m wild guessing a possible reason. The Demo account gives me a balance of 10,000 Euro. When I placed the order to sell silver, I was silly to set the volume as 14, as I didn’t know the standard lot of silver trading was 5000. (And thank god it’s only demo!) 
So when the position opened and the price obviously went opposite way. If the price continued to go the wrong way, my balance would go minus. 
Was that why it closed the position so early?
 

When you open a position and the price moves against you beyond the free margin, you should get a mail notification from that broker asking you to close your position asap.

Firstly, from what I read so far that doesn't seem to have happened to you. Secondly, even if the position was closed automatically for that reason, you should still be able to read your original SL/TP values in the history. Since these values are not present, I suspect something removed them as soon as the trade was open. Check the logs.

Reason: