Problem with stable works

Hey guys! I have problem with all my worker in one farm. Have line break as on image from 21:00 to 21:10. Have this for all my worker located in different locations but added in one farm. So it is no internet connections problem. Help me PLEASE, how can i solve this? Tthanks!

Same problem, 21:00 - 21:10 + 1:45 - 2:00