Nintendo Switch no longer recognizes games after a while?

I have the following request. For a few days it has been the case that my switch, after I switched it to stand-by mode or switched it off completely, no longer recognizes the game which is in the switch the next time I start it. So I can no longer activate stand by to continue playing next time. I hope you understand what I mean 😀. Does anyone have similar experiences?

🤔 Honestly, I haven't had the problem yet.

My approach would be:

Switch off the system completely (press and hold the off button) and wait 2 - 3 minutes
Take out the cartridge
See if there has somehow gotten into dust or if the card is dirty.
Reboot the system
Look for new updates that have not yet been installed!

If you put the card in, will it be recognized?

Does the problem affect both download games and catridges?

Is it just one game or all of them?

In case of guarantee / warranty:

Look for the bill for your switch, does it still have a guarantee or warranty?
Is it just a game then also the receipt of…
Then contact Nintendo before you try to fix it yourself and the warranty runs again.

No guarantee:

Sounds like a contact error. Either the rear of the cartridge is dirty or something is bent. You might have to clean it, like the DS, 3DS cartridges (cards) used to be. For this I would use alcohol or WD40 which is suitable for electronic parts. (What you use, for example, with the Joycon drift! According to Nintendo, you lose your warranty!)
Do not use too much pressure so that nothing breaks away. And only take funds for electronic parts!

If there's a guarantee, please contact Nintendo repair service first! I've had good experiences with it. My red Joycons from the Nintendo Store were defective. They had detached themselves from the screen without clicking the button and the Joycon Drift within a week I had the Joycons repaired back. (I wrote down the problem in detail with all errors per Joycon)

MichiruKaio has already explained it very well but I can only share my experiences. If the cartridge is not read in my case, then I usually just try to put it out and back in again (sometimes even 20 times, no idea if it's ok) and I blow into the cartridge slot (if there's dust there) and sometimes I turn off my switch or press restart and then it works. Try it this way first (if you haven't done it yet and are unsure about the WD40 stuff)

Getting cards in and out 20 times can of course help. But it's rather annoying. 😅

Most importantly, it doesn't fix the problem…

But yes, use products like WD only with caution, at best watch a few YouTube videos before cleaning or contact Nintendo. In my experience, they want to help.