The controller (using the latest firmware) does seem to support running 4 blades. But it seems running 4 blades only works if you're running them off a single power supply.
Your miner status seems to say there are four blades connected to the board (I assume this is not true, please confirm) which is weird.
Your status reminded me of Tupsu running 4 blades of a single controller. When they used two separate power supplies their miner status looked exactly like yours:
Was this with the new firmware or the old one?
Also, what do you mean by after overheating?
I changed the picture. Fan failed and first miner overheating.
New firmware. Works only with single power supply.
With two power supply 2 boards failed.
The difference in load also seems to point to a failure on the controller board... You might want to try to run the blades on a controller that you know is good, just to be sure the controller is the issue.