Second screen goes into sleep mode unexpectedly

there are 2 possibilities:
- clone: what is displayed on the first screen is also displayed on the second one (basically, we have the same thing twice)
- dualview: here we have two distinct displays, and we can move windows from one screen to the other
which one is yours?

try this
In the Control Panel, open Display Properties.
Click on the Settings tab.
If you are using the multi-display feature, click on the icon corresponding to the monitor for which you want to change the settings.
If you are not in safe mode, complete each of the following steps. (In safe mode, these settings are already set to the minimum values.)
In Colors, click on a lower setting.
Reduce your desktop size by dragging the Screen resolution slider to the left.
Click on Advanced, then look for a Refresh rate setting in the Monitor and Graphics tabs. If this setting exists, lower the refresh rate or use the default value of the card.
After making your changes, or to accept the safe mode settings, click OK. Restart your computer if prompted. Do not select safe mode.
Notes

To open Display Properties, click Start, then Control Panel, then Appearance and Themes, and finally Display.
Warning

Setting a refresh rate too high may permanently damage some older monitors. Do not set a refresh rate higher than the limit specified in the documentation provided with your monitor.

Does changing the display settings resolve the issue?

re
otherwise try this thing in trial version -------->http://www.softany.com/MonitorControl/index.htm
after that it's paid
bye

I will try your first method to see if that's where it comes from.
Thank you for your help.

The first method is by Bill Gates, oh, it's with the help of Windows
great.