According to this redditor https://www.reddit.com/r/Qubes/comments/sttorm/comment/hxtt5en/?utm_source=share&utm_medium=web2x&context=3
“it was answered here https://www.reddit.com/r/Qubes/comments/sttorm/comment/hxmefo0/?utm_source=share&utm_medium=web2x&context=3 . It happens because sys-whonix trys to update the time in those VMs and therefore restarts them.”