Hi @Tefal , I agree you can lose money quickly, especially if not disciplined/understand the stock(s) you’re playing. Should you try the practice account again, i’d suggest reducing the amount you are playing with, or your position size.
when you’re more confident with the stock market/trading you’ll likely view CFD’s in a different way. I adore it, and hope T212 puts more effort into their CFD platform by adding more Stocks, and Extended Hours… but i won’t hold my breath as all discussions and efforts seems to be around Invest and Pies 
I never found out the reason why i couldn’t go long, i can only assure you that it wasn’t limited funds/blowing up my account 