AP is significantly lower than other methods,please help me

[huoyiyang]

Thanks for your error report and we appreciate it a lot.

Checklist

1. I have searched related issues but cannot get the expected help.
2. The bug has not been fixed in the latest version.

Describe the bug I use my dataset with coco dataet format, other method such as mask rcnn , gc net ,yolact implemented by mmdetection all work well. all on colab! but when i use in solov2 1x r50 ,there are several question! (1)the loss_ins can not decrease , so i try to change lr, the loss can down,but still stop at around 0.3 (2)the test AP is significantly lower than other methods,about 20% (3)i try to change the hyperparameter grid ,i enlarge them ,it seems useless

Reproduction

1. What command or script did you run? !python tools/train.py configs/solov2/solov2_r50_fpn_8gpu_1x.py

2. Did you make any modifications on the code or config? Did you understand what you have modified? i change the lr ,with your origin lr, the loss_ins stay=3

3. What dataset did you use? my dataset ssdd ,no problem Environment i change your modified code to torch 1.4,torchcheck to atcheck

Error traceback If applicable, paste the error trackback here.

![image](https://user-images.githubusercontent.com/73746988/122396688-d3d0d280-cfaa-11eb-89ad-f2c80b174268.png)

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Bug fix If you have already identified the reason, you can provide the information here. If you are willing to create a PR to fix it, please also leave a comment here and that would be much appreciated!