loss can't converge and all detect results are 15(person)

[maxlchina]

I changed the backbone net from VGG to mobilenetV2, but loss can't converge. when test the model in pre, i found all results are 15(person), what's wrong with this work?

[DamonDBT]

When i run the origin code, i get the same problem. Have you get a answer now ?

[Gausshy]

I changed the backbone net from VGG to resnet, i get the same problem.