The starter is excellent. However, as a complete novice I found the instructions very sparse and a little confusing. As I said in my email to you, it would help to add the following points -
Prepare in a warm temperature - if kitchen is below 20 deg. fermentation slows drastically. Bring the starter out of the fridge and feed at warm temperature.
Keep dough consistently warm 24-26 deg. during bulk fermentation. Warming oven?
Water should be around 28 - 30 deg. to create dough at 24-26 deg.
If in fridge, either reduce fridge time or make sure fridge is genuinely cold 3-5deg.C
Use rice flour in proving basket not wheat flour as it sticks less. Do not use detergent when washing banneton liner. Allow any excess dough to harden then brush off.
Before baking, poke dough - should spring back slowly but not fully if it’s ready.
Watch dough, not timings.