Not satisfied with overall results of the model.

[sparshgarg23]

So I was able to finish the training of the model for roughly 280,000 iterations and I am not satisified with the overall results of the model.
The overall mean AP for resnet50 with batch size set to 6 comes out to be only 27% with the AP for the smaller objects coming out to be only 9%.

Any reasons why this drop in AP is happening,is it because of the batch size .
I noticed that whenver I resume training,instead of resuming from where it left off,it starts at iteration 0.
An example of the instance segmentation on coco image is shown below
Original image

Result image