PC slow when waking up from sleep

Hi,
I'm having an issue with applications (seemingly those involving networks?) being extremely slow when my e-7240 Latitude returns from sleep (i.e., reopening the computer's lid). I've tried and completed all items mentioned here except for the New User Profile and Restore System options (and of course OS reinstall) without success. I know there are posts here on that topic but I haven't found a solution there either.
The only things I can remember having done before the issue appeared was to try to install WebPresenter drivers, which partially failed (but I have since uninstalled those drivers that were installed), and plugging in the power supply with the battery removed. Incidently, in the latter case the symptoms were pretty much the same as now, i.e., recovering from sleep. As I seem to understand that CPU power is limited when no battery is present (am I right?) or during sleep mode, it may seem that full power to the CPU is not restored when coming ou of sleep, but this is just a wild guess.
Anyway, this is a real problem for me as I like to "close the lid" when I'm away for a short time, so I'd be really grateful if some genius out there could help me fix the issue, or at least provide some suggestions.
Thank you for reading me!

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Powercfg -a shows same as Brink's (link) except that available modes says (translating from French): sleep (or standby?) <S3> Hibernate - Hybrid mode sleep (note that Hibernate is deactivated in my Power Settings)
S1 / S2 not supported (is that definitive or can it be changed? I would have liked to try them...)

During sleep mode, almost everything is turned off or run on a very low state.
Yes, CPU runs on a very low state (even the fan is turned off) but doesn't depend on the power source and once awake it runs on the same manner before entering the sleep mode.

As I mentioned, many hardware components are turned off, like USB, HDD, LAN, WIFi etc.
Even when waking up, if the computer relies on external devices it can take some time to recover (as for example, log in on a domain).
You can see what is turned off during sleep on the power options
Control Panel\All Control Panel Items\Power Options\Edit Plan Settings - Change advanced power settings

Megahertz07 said:

once awake it runs on the same manner before entering the sleep mode.

That's what I would like to have...
I did a bit of timing, which shows time to load an Excel-365 50-KB file normally = 3 secs, which becomes 23 secs after wakeup, and to load my browser (Vivaldi) = 6 secs normally and 53 secs after wakeup.
And this'll last forever until I reboot the machine...

Opening programs is more related to drive performance. You have a mSATA 128 SSD, correct?

Change the power plan to High performance. Change the Control Panel\All Control Panel Items\Power Options\Edit Plan Settings - Change advanced power settings and set Hard disk to 0 (never).
Then go Start - Shutdown button - sleep and then wake it up.
Report

My power manager doesn't allow me to do that, it always reverts to standard mode. Strange...

Lets do the basic.

Open a CMD window as administrator and type:
chkdsk c: /f
It will say your disk is in use and ask if you want to schedule to next start = yes
Restart
Pay attention on the results, specially bad blocks, bad clusters, bad sectors etc

Back to Windows, open a CMD window as administrator and type:
sfc /scannow

If it finds any corrupted files, fixing or not, reboot and run again

Check the power configuration settings. There is a setting on what to do when closing the lid. Change it, reboot and change it back.

Tried that, didn't help.
Edit: going into sleep mode with the power button does the same as with the Windows button, i.e., no problem.
I'd like to understand what the difference is between sleep modes when started by either button or lid actions (didn't find anything on the Net).
Unless decisive tests are suggested, I would suggest to close this thread as [unresolved], as for now I may simply press a button before closing the lid...
For curiosity, I may request help from Dell.
@ MHz, thanks for trying!

The power button or the lid starts with a hardware switch and then it is treated by software.

It must be a logical (software) issue