Sorry, I know this is an old post, but I believe many people still come through here looking for an answer. So I’ll post.
The problem is that there is a mismatch in the sample rate of the Interface and the Cubase project. Eg. The interface might be clocked at 48kHz while the project is set to 44.1 or vice versa. That will cause an audio track to record but show now signal present in the wave and when you stop recording, it disappeares. (it’ll still show up in the audio pool, but the track lenght will be 0.00s)
How do you confirm this is the problem? Change the audio driver in (Device setup) to say, ASIO FULL DUPLEX and record something of that… It should now record as usual, but not when your interface is selected. If that happens, its sample rate mismatch.
You’ll have to match the sample rates then save the project and close. Then restart cubase or maybe even the entire computer. To match, open project settings, where it says 44.1 or 48K, match that to what your interface is at. (it might be orange in color) indicating there is a mismatch. I’ve had that even when the samples rates are the same. Cubase is just not seeig the sample rate of the interface yet and therefore “thinks” they are mismatched making them orange. When you’ve set them te same, save the project and close Cubase. Restart te computer and re open the project (just restarting cubase might nog work). It “should” now open in the new sample rate looking for the interface and connecting properly, fixing the issue and detecting inputs.
Hope it helps.