I honestly can't figure it out. When I form a ball to put it in the banneton, the seam just opens up and splays out. My breads still come out pretty good but I think this could lead to some improvement. It has led to some lopsided breads (when they're small) because it opens up so far. It's very frustrating. I don't use any extra flour or anything. As far as oil...I will sometimes lightly oil gloves if I dont feel like getting my hands dirty for stretch and folds but I cant imagine this is an issue. Thanks!
What is the hydration. Sounds a dry dough to me.
Some pictures would really help here.
as would a formula and procedure for the bread in question
How are you shaping it? I know that what's happened for me is that there is an ever so light coating of flour on my countertop that reduces friction too much while I'm trying to shape my loaf, preventing the seam from properly closing. I've solved it by having a damp towel nearby and quickly wiping down the countertop after I've floured the dough and before I round the loaf.