Child tax credit and stimulus checks. ?

The stimulus checks do not reduce the child tax credit at all.

If they disappeared, there is either a software glitch or user error.  Reenter.

Parents who are eligible for both stimulus checks and the enhanced child tax credit should see direct assistance this next year of between (depending on the age of their children) $4,400 to $5,000 per child. That's in addition to their own $1,400 stimulus checks, plus a stimulus check for any adult dependents.

has nothing to do with the stimulus checks, something else is wrong.

Stimulus is a loan and is paid back from tax credit. So whatever you got from stimulus is subtracted from tax credit 

That isn't right. The stimulus checks would not affect the child tax credit in any way. Rather than just looking at the number on the screen, look at the 1040 form itself to see if the CTC is still there or whether it moved to the additional child tax credit further down the page. There also should be a worksheet for the CTC and ACTC. Review that as well. It may be that you checked a box that shouldn't be (or didn't check one that should be) or entered something on the wrong line.

The CTC doesn't have anything to do with the stimulus checks.