God! seems that the 7800 buy was not at upcoming immediate order but a long opened 2 days ago, during the dump 2 days ago, where kraken website was not responding and I had many troubles to make my trades in that time. There were many duplicated orders for the failed attempts, and after I finally could do my trading (late because kraken failures) I cancelled all duplicated orders.
Now support is telling to me that there was still one long already opened at 7800 since then, but this order WAS NEVER BEEN SHOWN at the orders list.
BEWARE TRADING AT KRAKEN. The platform is FULL OF ERRORS which will make you lose much money and they do not assume the liability.