signs of fraud

Around the beginning of April, I met a girlfriend online, she introduced me to the exchange, more than a month of profit, I made a withdrawal order but Cskh forced me to pay a security deposit because of the owner's main account. I have 2 payers, me and my girlfriend, to support me. I saw signs of fraud, so I found out that the mt5 software was also fake. I live and work abroad, how much money I send back is confirmed by the bank, so why not let me withdraw money at first, I thought Cskh was a foreigner, so I had to fill in Vietnamese clearly (for google to translate correctly) but now I abbreviate it, they still understand. Signs of fraud