A problem of both taking screenshot and screen recording not working

Hi. This is Lee from South Korea and I want to have your wonderful ideas and solutions which I have been actually experiencing since last month.

My iPad has a problem of not working on both taking screenshots and screen recording functions. I tried everything but to no avail including the following instructions found in the internet.

1. Press down the Power button and Home button simultaneously as usual, but press the Home button one second after pressing the Power button.

2. Force restart the iOS device: Press and hold the iPhone or iPad's home button and the power button for at least 10 seconds, please to force restart the device.

3. Take screenshots with Assistive Touch

4. For iPhone 6s and later, you can add Screenshot to 3D Touch Actions to take screenshots: Setting > General > Accessibility > Assistive Touch > enter the Customize the Top Level Menu> 3D Touch Actions > and check the "Screenshot". Then press strongly on the Assistive Touch icon and the screenshot should be taken.

Former time, sometimes I found the screen recording not working in case ipad’s available storage was not enough. Then I removed some big files from iPad and I could do the screen recording. But this time I did the same thing, but that could not solve the problem and this time both functions of taking screenshots and screen recording do not work at all. But I can still take pictures and there is no problem of taking pictures except of taking screenshots. I even deleted many big files from my iCloud which was full at one time, but the problem is still there.

I worry this could be a sort of hardware problem. Or will it solve the problem if I try the factory reset? Any wonderful ideas or solutions to this matter? Thank you in advance!

Lee,