Update
Well I’ve been making this bread a couple of times a week for a few weeks now and I’ve come across a few tweaks to the recipe that seem to work for me that you may want to use as well:
1) I typically increase the amount of yeast from 1/4 teaspoon to 1/2 teaspoon - it seems to rise a lot better and give a greater texture
2) Make sure that the flour is all combined - add a little more water if you have to, otherwise the uncombined flour will cause lumps in the bread
3) Only use wheat flour or the recipe doesn’t work properly. Spelt or Rye flour does not contain gluten in it so it doesn’t react with the yeast as it should. Having said that I have successfully used a mix of 2/3 wheat flour and 1/3 rye flour for a more dense rye type bread.
4) Make sure to leave it in the oven for the full 30 minutes, the times I took it out early because I thought it was getting too done on top the bread wasn’t cooked all the way through.