I just checked that the SSH server is working in the 188.8.131.52 machine, could you please access that instance and run the following commands (please share their output with us. They will possibly include passwords, please remove them before sharing):
sudo /opt/bitnami/ctlscript.sh status
sudo /opt/bitnami/ctlscript.sh start
sudo cat /opt/bitnami/var/log/*
Can you access the application now? I included the start command to start the services, this shouldn't be needed though.
Apart from that, we have a Support Tool that will gather relevant information for us to debug the issue. Could you please download and execute it on the machine where the stack is running by following the steps described in the guide below? You must click on the platform or cloud that you are using to find the correct instructions.
How to Run the Bitnami Support Tool
Please note that you need to paste the code outputted by the tool in your reply.
Finally, in the networking section, can you check that the firewall is properly configured? In which region did you launch the image?