What is the problem with KuCoin?

Could you elaborate on the issues currently facing KuCoin? Are there any notable security breaches, customer service complaints, or trading issues that have been reported recently? Additionally, how does KuCoin's performance compare to other major cryptocurrency exchanges in terms of reliability, fees, and the range of digital assets available for trading? Understanding these potential concerns can help investors make informed decisions about using KuCoin as their trading platform.