Salt bread turning out bad

I don't have a photo to show sorry. But Ive made korean salt bread 2 times, the first time using all purpose flour. I baked it and then it came out raw-ish on the inside and brittle outside like a biscuit. I thought it was the flour but I tried a second time with cake flour and bread flour, but it had the same result and my bread turned out brittle outside and raw inside.

i followed all the steps to erins cozy kitchen recipe but the dough never does window pane it ends up ripping even if i let it rest. I dont know if my ovens the problem or the dough.

pls help mee