DBSCAN doesn’t perform any dimensionality reduction. So probably you’re making some mistake. You can follow this Scikit-Learn demo (https://scikit-learn.org/stable/auto_examples/cluster/plot_dbscan.html#sphx-glr-auto-examples-cluster-plot-dbscan-py). StandardScalar method when applied to features of your data, it removes the mean and scale them to unit variance. Check this (https://scikit-learn.org/stable/modules/generated/sklearn.preprocessing.StandardScaler.html). Hope you will be able to successfully apply DBSCAN on your data-set.