When using Portainer you need to understand how it configures the “stacks” and the file locations
I dont use portainer as I dont see why you need a gui to do stuff 
However, when helping other users (I cant exactly remember) but there is a directory for the stacks and within there it mounts the points you define using the UUID of the stack. (I might be wrong since you are using full paths but I remember that there was an issue when users were recreating the stack crowdsec would loose the files since the UUID changes per deploy)
But in short you would need to mount the logs into the crowdsec container and from your main stack you are mounting to host (portainer) via /home/ubuntu/cloud/logs. However they are not being passed to crowdsec.