I'm using Tor (Orbot for Android), and when I look at the log of the connection establishment phase, I see that I'm repeatedly being connected to familiar nodes, especially the Entry Nodes which 3 out of 4 times are the same 3 nodes that I'm connecting to every time! Even the whole 3 Nodes in my path are more often than not also familiar and so much so that I almost see no randomization process happening!
I understand that if 1 malicious node is in my path, my anonymity won't be much affected, but if at least the Entry and the Exit Nodes are malicious, then I'm not anonymous anymore since the entry data and exit data can be monitored and compared.
Question is: How do I force randomization of the connection, and WHY am I being assigned these nodes repeatedly (i.e. is there a known attack in which an entity can deliberately assign users to specific ranges of nodes to strip them out of their anonymity?)