No bubbles detected at all when 'splash' or 'detect' is executed as per demo script

[dainakai]

I have set up a Python 3.7 environment using Conda and installed the necessary CUDA libraries via Conda. After that, I installed the following packages using pip to meet the requirements.

# requirements.txt

numpy==1.16.4
scipy
Pillow
cython==0.29.21
matplotlib
scikit-image
tensorflow-gpu==1.14.0
keras==2.2.5
opencv-python
h5py==2.10.0
imgaug
IPython[all]

I downloaded mask_rcnn_bubble.h5 as instructed in the README.md, but when I run the splash or detect script, no bubbles are detected at all.

Only when I set the confidence to 0.5 do masked areas start to appear, but obviously, this is not meaningful.

What could be the problem? I would like to know the versions of all the installed packages in an environment where it executes correctly.