Same here, it was an A321, MSN 990ish, now scrapped. And I actually found a file with values I marked down then
G5Gm.png
The amount "missing" would increase until about 8t FOB, then come slowly reappear and by 4000 kg all was back. The more you had at the beginning, the more was missing by the time you were down to 8000. Ad extremis 900 kgs!