On the Dell P2422H Monitor itself (its settings) turn off Deep Sleep (or similar wording).

Are they under warranty?  Open up a support ticket via chat using the blue button on the bottom right.  If the blue button isn't on your screen, you can still open up a service request.  You might get asked for service tags, no posting them here (private info).

I'd also like to suggest getting away from the micro's and using SFF's.  Some micro's have been difficult to troubleshoot.

Is the monitor going to sleep while the PC is still awake?  Set standby/sleep times same for PC and monitor.  Something else that might work is set auto sleep to Never for PC and monitor.  PC and monitor can still be put in sleep mode by using mouse and going over to the power options (Turn off; restart; sleep), or use sleep button on keyboard if you have one.  

@Tesla1856 - I could not find any sleep-related setting in the menu of the P2422H.

@bradthetechnut - I'd have to check to see which ones are still under warranty or not. I know that this issue is happening on all our deployments that use that model of computer and monitor. I definitely agree though about moving away from micros.

The monitor goes to sleep (per what is set in Windows power settings), and the computer does not sleep. 

My other suggestion was going to be try a different monitor and see if the behavior is the same.

Hello @GundamEpyon , the issue could have been caused by extremely low power during idle.  The hardware set to turn off and be disconnected and it has detected active signals, then turning back on again.  If you haven't try this yet, go to the old Control Panel and Power Option, set Power Plan to High Performance.  On some Micro systems, you may need to create a new power plan to see the option for High Performance.  That should increase the consume power a bit, enough to fix your current issue. 

You might keep the default settings, put monitor to sleep in 15 minutes, turn off computer =  never.

This issue seems oddly similar to the following thread:

Laptops beeping after update when connected to multiple monitors and docking station

However, as far as we are aware, this only happens while using two monitors in a daisy‑chain configuration. Specifically, under these 2 scenarios:

• Laptop or desktop connected using USB-c or Thunderbolt to two monitors using MST (Daisy chain)
• Laptop or desktop connected to Dell dock (WD19/WD22/WD25/SD25 all versions) and two monitors are daisy chained through the dock

Are you using a daisy chain setup with the P2422H monitors? Using the DP ports should also not result in this beeping. The above scenarios have been found to be an issue with the GPU drivers and we're working with Intel for a driver fix for that specific situation. Try installing this GPU driver on a system to see if it resolved the beeping. If this does provide a fix, then it would seem we may be under the same issue. 

@GundamEpyon​  One of Chino's suggestion is similar to mine.  Setting Power Plan to High Performance also means auto sleep will be either set to never or a long duration before auto sleep kicks in.  I haven't played with for a while.  For all I know, it will set PC to Never and still have sleep set for monitor.

One of my suggestions is still the same - try it with PC and monitor set to Never for auto sleep and have it set to High Performance as Chino suggested.

Hopefully I didn't miss anyone for this reply:

@bradthetechnut – Sorry, I’ve been out. I was just now able to resume troubleshooting. I had grabbed a Dell E2020H monitor, and the issue is not replicated. I used the exact same DP cable, as well. So far, the issue occurs only when we use the Dell P2422H monitor.

@Chino de Oro – I had tried the High Performance power plan, as well as disabling/change any power-saving option I saw in advanced power settings. The issue still occurred.

@DELL-Daniel V – There is no daisy chaining in place. This issue occurs on all of our deployments that use the micro form factor Dell system and the paired P2422H monitor. We have entire classrooms that have the issue that used that pairing. Sounds like a symphony going off until the monitor is woken. I can confirm no Dock is being used with this desktop/monitor combos. I have tried disconnecting the USB-B cable from the monitor and system, as well.

The two Intel UHD Graphics 770 drivers I have tested are 32.0.101.7077 and 32.0.101.6556. I will try the version you linked (32.0.101.7026), and will post a new reply with the results.

@DELL-Daniel V - I can confirm that the issue still occurs when using the Intel UHD driver 32.0.101.7026. However, something did change. Rather than the connect/disconnect sound repeating every 10 seconds, it did the following:

1. Monitor sleeps
2. After 1 minute, system emits the 1st connect/disconnect sound

3. Took 1min30sec~ for the 2nd connect/disconnect sound
4. Took 3min50sec for the 3rd disconnect/reconnect sound

5. Took 6sec for the 4th disconnect/reconnect sound

There is a lot of consistency with this particular driver, but it at least proves the behavior changes with a different driver version.