Why is everything slow at 2pm but fine at 8am?

A predictable time of day pattern is a useful clue, because it means something scheduled or behavioral is causing it rather than a fault.

The usual suspects:

• Backups or antivirus scans running during business hours. Extremely common, and easily the most fixable. These should run overnight, and on a lot of the environments we take over they are running at 1pm because that is when they were set up.
• Cloud file sync. Everybody arrives, opens their laptop, and OneDrive or Dropbox starts syncing at once. This bites hardest on connections with thin upload speed.
• Actual bandwidth saturation. More people working, video calls running, someone streaming. If your connection was sized three years ago and you have grown, you may simply have outgrown it.
• A database that has never been maintained. If the slowness is specifically your line of business application and it builds through the day, this is often it.

Worth checking yourself: does it get slow at the same time every day, or after a certain number of people arrive? Those two answers point in different directions and it is genuinely useful to know which before we look.