It might be that your max execution time for the workbasket is being exceeded. It may also be an issue with the bot itself. I would suggest that you open an SR with support and have someone look at your specific machines. If you do open an SR, please note the SR number here for tracking purposes.
The robot may have also exceeded it's "max assignment failure" threshold. What status code are you returning in your automation? If the Robot Manager does not receive a value of "Completed", it will consider the automation to have "failed" in some way.
If the maximum automation execution time is exceeded and the bot has turned red owing to poor health now, is there a way to reset the bot or turn it green once again. I could find a way to do that by deleting the corresponding operator record from Pega [Not sure if there is a better way to reset the robot at this time]. This allows the robot to launch again and PEGA re-creates the robot operator record upon login. But how else can we turn this green once again as it wont be monitored for each n every case in production.