After working with semolina doughs regularly over the last year, I can tell you from experience that the dough is a bit heavier and needs a bit more hydration than other doughs to get optimal results. For my 100% semolina doughs, I am typically around 72-74% hydration and between 68-70% for a 50/50 blend with AP. This flour absorbs water much more slowly than other flours too. So once the dough has been lightly mixed, I will normally let it autolyse for 10 mins before proceeding any further.
If it helps, the workflow I have been using for semolina doughs are to add all the water to 90% of the flour in your formula. I mix the flour and water by hand till it forms a mass and let it rest for 10 mins. After 10 mins, I mix in the remaining 5-10% of the flour (depending on how the dough feels) and let it rest for 10 more mins. From there I will do a series of stretch and folds to lightly develop the gluten. I do not like using mechanical means of mixing in this instance as I find that the dough becomes too tough.
If your final product does not come out as planned, don't give up on semolina. Since I have been trying to develop my VPS (Vera Pizza Sicilia) recipe, I have became hooked on the flavor and textures that can be coxed out of semolina breads and pizzas, but it does take a bit of patience and practice to achieve good results with this flour.
The dough formula that has worked out really well for me in the past is:
100% flour (60% durum and 40% AP)
70 % Water
.3% IDY or 5% starter
1% olive oil
Below are two such examples from this recipe.