Consistent FBA receiving discrepancies, units lost

I continue facing issues with stock receiving at Amazon warehouse. Right now I have 3 claims rejected by amazon amounting over 7000AED and approx 210 units pending receiving.

I would like to understand what causes the receiving issue. I purposely send smaller shipments daily thinking whoever receives the shipment can scan it quickly in a few minutes, however this doesn't seem to work. I have attached the picture of how I pack my items, I bubble wrap it and put the label on top.

How I pack the shipments is:

1. Fill a box with products to ensure the box is full.

2. Take the items out 1 by 1, create the packing list and record the ASINS and quantity on Amazon portal

3. Print the labels, stick it on each item, put them back in the box. This way I can ensure an exact match of quantity in the box and on the PO.

The amount is too high to just take it as a loss. I already get several return every month where the products are used and returned that I have to write off, I can't take thousands in loss for misplaced inventory too.

These are the rejected claims:

1. FBA15JFF21SW: shipped on 28th August, lost for 51 days, 29 units partially received on/after 18th October, 2 units more received which is NOT my item. Claim rejected for 47 units.

2. FBA15JL47SQ5: shipped on 8th October. Claim rejected for 7 units.

3. FBA15JL9SD4R: shipped on 9th October. Claim rejected for 15 units including some gift sets what are high value.

Since there are currently ~210 units outstanding for later shipments I am expecting many more missing units, which will cause further thousands of dirhams of loss.

Therefore I'm asking for your help to resolve the claims and try to understand how to avoid shipments not being received in full.