Hi @olibclarke,
I think we may have found out the cause of this discrepancy. Based on the pixel sizes in the 2D class event log you attached, it looks like downsampling was likely used. Unfortunately the implementation of remove duplicates in 2D Classification (in the case of downsampled data) uses an incorrect pixel size when converting particle coordinates into physical angstrom distances, and this would cause it to reject way fewer particles than expected. We’ll aim to fix this in an upcoming release, and thank you for your detailed reports as always!
Best,
Michael