Um - you seem to have confused the words. Genesis says that God made a hard dome - a raqiya, and named it "Shamayim" or sky. It's still a hard dome, just as if I named my car "Fred" - it's still a car. You've mixed up "hard dome" (raqiya) with the name given to the hard dome (shamayim="sky")
I looked at several modern translations, and it's pretty clear:
Good News Translation:
Then God commanded, “Let there be a dome to divide the water and to keep it in two separate places”—and it was done. So God made a dome, and it separated the water under it from the water above it. He named the dome “Sky.”
ISV:
So God made a canopy that separated the water beneath the canopy from the water above it. And that is what happened: God called the canopy“sky.”
CEB:
God made the dome and separated the waters under the dome from the waters above the dome. And it happened in that way. God named the dome Sky.
NRSV:
So God made the dome and separated the waters that were under the dome from the waters that were above the dome. And it was so. God called the dome Sky.
As pointed out before - it's not "some liberal university" saying that. It's the literal meaning of the text, and the reference I supplied to show that is a peer-reviewed paper - meaning that this is agreed up by many Biblical scholars, who actually read Hebrew.