Hanfire All recurring jobs ran over the weekend at the same time and system crashed

I have 20 Recurring jobs that runs different time frame over the week days. I have been using those jobs from over the years and All of sudden last week saturday, all job ran in same time 2:00 AM.
All my recurring jobs ran at the same time exactly 2:00 AM over the weekend and crashed application completely.

Question:-

  • I do not have even job for weekend, all jobs runs on week days.
  • Why all of them ran at same time even they have on separate time frame.
  • I have been running this jobs from several years and never had such issue and why now ?
  • what can I do to stop such inception?