Lightroom classic goes into import screen every 30 secondes without asking

Problem solved. Option preferences was unchecked.

Try unchecking the option Preferences > General > Show Import Dialog When A Memory Card Is Detected.

Windows is repeatedly telling LR that a new drive is connected, and with that option set, LR dutifully opens the Import window.  A couple of possibilities:

- You have a loose hardware connection (e.g. a cable) to a card reader or external drive that jiggles and causes Windows to reconnect to it.

- You have a software utility that is creating a new virtual drive every 30 seconds and then disconnecting it.  Over the years there have been reports of a couple such utilities.

If you open File Explorer while this is happening, you might be able to see which drive is getting connected repeatedly.