DBSCAN not working properly

I am working on writing a DBSCAN algorithm for data clustering. I am writing it from scratch because 1.) I am working with Matlab 2018b, and 2.) I would like to fully understand the algorithm. The script creates cooked up data that i feel should be easy for the algorithm to cluster properly, but when i run it, i get some undesirable results (i.e. Data that clearly belongs in one cluster is clustered into more than one cluster). I have tried many selections of Epsilon and Density that should give me good results. The algorithm performs well on the first cluster, but less so on the subsequent clusters. I can't determine what is going on in subsequent iterations that would cause this.