Can't curl Docker Containers

Question

I'm trying to setup docker on a company VM on Ubuntu 20.04.
At first I couldn't even start the service because it seems there was a conflict with the pre-existing routes. If I run the route command I get this:

Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
default         0.0.0.0         0.0.0.0         UG    20     0        0 eno3np0.1169
10.0.0.0        0.0.0.0         255.0.0.0       UG    20     0        0 eno3np0.1169
100.64.0.0      0.0.0.0         255.192.0.0     UG    20     0        0 eno3np0.1169
100.99.0.0      0.0.0.0         255.255.0.0     UG    20     0        0 eno3np0.1169
172.16.0.0      0.0.0.0         255.240.0.0     UG    20     0        0 eno3np0.1169
192.168.0.0     0.0.0.0         255.255.0.0     UG    20     0        0 eno3np0.1169

I was able to find a solution by specifying a different network in the /etc/docker/daemon.json:

{
    "bip": "240.0.0.1/24",
    "default-address-pools":[
        { "scope": "local", "base": "240.0.0.0/16", "size": 24 }
    ]
}

However, I've tried running a few containers, but it seems that I cannot reach them.

For example:

CONTAINER ID   IMAGE               COMMAND                  CREATED       STATUS       PORTS                                   NAMES
198ae3884ac7   tutum/hello-world   "/bin/sh -c 'php-fpm…"   3 hours ago   Up 3 hours   0.0.0.0:8081->80/tcp, :::8081->80/tcp   helloworld

If I try to curl it, it just hangs forever.

curl localhost:8081 -v
*   Trying 127.0.0.1:8081...
* TCP_NODELAY set
* Connected to localhost (127.0.0.1) port 8081 (#0)
> GET / HTTP/1.1
> Host: localhost:8081
> User-Agent: curl/7.68.0
> Accept: */*
> 

I'm not sure how to proceed from here. Any suggestions on how to further debug the issue would be helpful as well.