Installing second motor on shutter

Hello, I have installed a second shutter motor controlled by a second driver TB6600. I wired the signal ports from the original driver parallel to the second TB6600. I connected the second motor on the power side of the TB6600 and i inverse the red and blue wire to make the motor run same direction as the original one. Everything works good when i use the rocker switch on the shutter assy, i open the shutter and when reaching the sensor it stops, the same when i close it. When i connect the pc via Device Hub, if i command to open i just hear a clic and nothing move. then I open the shutter completely with the rocker switch and then command the closing via pc and it close but trying to reoppen it via pc does the same clic and nothing move. I can see something different from the past : I do not see anymore the shutter position on the nexdome window ?? I dismentle all my new hardwares and tried it with the original config and the problem is still the same. I updated the firware but no result ?? did someone do this modification and what is your opinion about my problem ?