PYNQ-Z2 HDMI Processing - Blockage after Image Processing IP

I am trying to do a project where I accelerate canny edge detection on PL and control it on PS

The image version on my board is 3.0.0
I am using Vivado 2019.1

For the IP core, I used the one from this github project:

Since I am using Vivado 2019.1, I re-generated the base ovelay from PYNQ image V2.4
I placed the IP core within HDMI-in, after pixel_pack, as mentioned in the official documentation

However, it seems the processing gets blocked
This is my jupyter notebook code

This is the output I keep getting:

Any ideas on how to solve this ?