When you look at the master clips of the MXF files you brought in – what is the source ID being tracked on those? You will find that in either the TAPE or SOURCE FILE column. Then look at your EDL and make sure that it matches the names in other one of those columns. If so, highlight your sequence, highlight all those master clips, then do a relink, but in the dialog box, do a “relink to selected” and work the settings from there. I recently did this myself.
Michael