Acer monitor R240HY keeps turning off with Macbook Air

tfh5

I have two Acer R240HY monitors (L and R) set up as an extended display, to which I connect my Macbook Air through a 4URPC docking station. I connect the monitors to the docking station with two VCA-HDMI cables (VCA ends to the monitors, HDMI ends to the docking station). My lefthand display has been fully functional. My righthand display keeps turning off randomly, displaying "No Signal," and I have to disconnect and reconnect the docking station from my Macbook to get it back up each time this happens, then it'll be fine for a while, then go dark again. I've tried freeing up disk space, power cycling the monitor, and replacing the cables, but I've had no luck. Any fixes would be sincerely appreciated!