The adjustment knobs on your Keystone Montana 2019 ISD slow rise night shade are designed to fine-tune the shade's speed and stopping position but do not restore lost internal spring tension. If the shade won't roll up or hold position, it typically means the internal spring has lost tension or become disengaged. To fix this, carefully remove the shade from its brackets and manually rotate the roller in the roll-up direction several times to re-engage and tighten the spring. Keep the spring wound while reinstalling the shade and then test its operation. If manual re-tensioning does not resolve the issue, the spring mechanism might be broken or worn out, requiring replacement of the roller mechanism or the entire shade. Elkhart RV Parts offers OEM replacement slow-rise roller shades and components compatible with your model.