Unexpected dataloader_idx_X added after log_dict.
🐛 Bug
Trainer is adding dataloader_idx_X to metrics, but it is not supposed to since the name of my metrics are data1/x and data2/x. It currently displays as data1/x/dataloader_idx_0=3.46e-14, data2/x/dataloader_idx_1=3.49e-14 in progress bar.
To Reproduce
https://colab.research.google.com/drive/1L_0LOl7pUeL7bzh6uZiRa3-WXYQQwirN?usp=sharing
Expected behavior
It should appear in progress bar the information as data1/x=3.46e-14, data2/x=3.49e-14 and ModelCheckpoint should find data1/x to save based on it.
Environment

CUDA:

GPU:

Tesla T4


available:         True
version:           10.1


Packages:

numpy:             1.19.5
pyTorch_debug:     True
pyTorch_version:   1.7.0+cu101
pytorch-lightning: 1.2.0
tqdm:              4.41.1


System:

OS:                Linux
architecture:

64bit



processor:         x86_64
python:            3.6.9
version:           #1 SMP Thu Jul 23 08:00:38 PDT 2020



Additional context
This was not happening before (I was using another version, but recently updated my pytorch lightning docker container), so I don't have working version information.