50MB/s without UAS, 100MB/s with UAS but getting disk drops

Hello everyone. Assembling an all-SSD RAID5 volume. During RAID volume creation, I got errors related with UAS (something about inflight CMD: IN). Disabled UAS and was able to create the RAID5 volume but the speed is 40% lower. What is the problem with the UAS? Is it the JMS561 firmware? Is it the USB3.0 Controller? @setq, can we get a newer firmware for the JMS561? I read online that there is a newer version that fixes the UAS issues but couldn’t find the download link for the firmware. I bought this board recently and the firmware is already at the version that is posted here on the forum.

Thank you