Hydroxyl groups like to interact with solvent so the chemical shift will depend on the solvent used. They will also interact inter and intra molecularly with other groups on your sample. Generally if they can form a hydrogen bond it will shift the chemical shift higher.

So the conclusion is OH protons can appear almost anywhere.

See attachment

When you used the NMR careful optimization of experimental parameters that influence proton exchange rates e.g., pH, temperature and nature of the solvent, results in slow proton exchange rates and, thus,

very sharp OH peaks. Thanks