Only one serial port on RBM33G

RouterOS RouterOS beta
1

RMB33G running v7.1beta2 only shows serial0. USB port shows usb2

RBM33G running v6.46.6 shows serial0, serial1 and USB port usb3

Is this a bug?

2

RBM33G seems to have some UARTs on J601 header.
rbm33g-serial.png