For what I understand, when she presented the second NOR she wasn't really ready, so that second NOR can be argued as non-valid.
A few questions. You say:
After tendering NOR, vessel was engaged at previous berth for about 5.50 hrs and then shifted to anchorage (shifting time 3.60 hrs) and awaited berthing.
Was the second cargo going to be loaded at the same berth as the first one ?
What was the reason for being "engaded at previous berth"? Was it your fault ?
If the answer to both is no, then our understanding for what we read is that NOR should have been tendered upon shifting anchorage, not before.