Inconsistent behavior with OCR technology

I am pretty new to UiPath. I am using UiPath community Edition for the POC purpose for my project. My application runs on citrix. I had to use OCR Images in various steps. When I run the scripts, the behavior is very inconsistent. It keeps on failing at different steps. Sometime it gets passed for all and it does not always fail at the same step. It certainly gets failed if the screen is resolution is changed. Even with same resolution, it is inconsistent. Can someone guide me what I should be checking or what could be wrong?
Thanks in advance.

Have you been through the Citrix training videos and Academy 1.0 and 2.0? These may give some more explanation. Citrix is hard to work with but it should be reliable if a) the resolution is consistent as you say and b) you use solid anchors to select text and elements.