Intermittent `localhost err_connection_refused` error on browser

jmajudd

Hello!
I know there are many articles addressing this already, but I haven’t found one to work yet so hoping someone can shed new light.

MM 2.7.0 on an RaspberryPi Zero W and chromium

MM was working after initial setup, I was tweaking modules just to get my initial layout all set (occasionally getting the “please use a config.js” message, fixing my js then it worked again…
So now the issue:
Twice now after pm2 restart mmrestart from just changing config.js I get the browser page that the Site can't be reached... localhost refused to connect

1st time it happened I started going back through the whole setup again doing npm install, etc and nothing worked. I was just about to burn the whole thing down when…
Finally after one more sudo reboot after no changes… it just worked.
This time, it’s not coming back yet.

tail -n 50 ~/.pm2/logs/mmstart-out.log:

wm_set_cursor_visibility: visible using XCreateFontCursor
Starting MagicMirror: v2.7.1
Loading config ...
Loading module helpers ...
No helper found for module: alert.
Initializing new module helper ...
Module helper loaded: updatenotification
No helper found for module: clock.
Initializing new module helper ...
Module helper loaded: MMM-CalendarExt
Loading module helpers ...
No helper found for module: alert.
Initializing new module helper ...
Module helper loaded: updatenotification
No helper found for module: clock.
Initializing new module helper ...
Module helper loaded: MMM-CalendarExt
Whoops! There was an uncaught exception...
MagicMirror will not quit, but it might be a good idea to check why this happened. Maybe no internet connection?
If you think this really is an issue, please open an issue on GitHub: https://github.com/MichMich/MagicMirror/issues
wm_set_cursor_visibility: visible using XCreateFontCursor
Starting MagicMirror: v2.7.1
Loading config ...
Loading module helpers ...
No helper found for module: alert.
Initializing new module helper ...
Module helper loaded: updatenotification
No helper found for module: clock.
Initializing new module helper ...
Module helper loaded: MMM-CalendarExt
Loading module helpers ...
No helper found for module: alert.
Initializing new module helper ...
Module helper loaded: updatenotification
No helper found for module: clock.
Initializing new module helper ...
Module helper loaded: MMM-CalendarExt
Whoops! There was an uncaught exception...
MagicMirror will not quit, but it might be a good idea to check why this happened. Maybe no internet connection?
If you think this really is an issue, please open an issue on GitHub: https://github.com/MichMich/MagicMirror/issues

nmap -A -T4 localhost:

Starting Nmap 7.40 ( https://nmap.org ) at 2019-04-24 06:55 EDT
Nmap scan report for localhost (127.0.0.1)
Host is up (0.0021s latency).
Other addresses for localhost (not scanned): ::1
Not shown: 998 closed ports
PORT    STATE SERVICE VERSION
22/tcp  open  ssh     (protocol 2.0)
| fingerprint-strings:
|   NULL:
|_    SSH-2.0-OpenSSH_7.4p1 Raspbian-10+deb9u4
| ssh-hostkey:
|   2048 66:12:9f:31:9f:17:1c:07:1e:f4:73:e5:66:95:ea:1a (RSA)
|_  256 17:08:1d:39:a9:ff:3f:1d:5a:66:c7:2a:e6:36:78:5f (ECDSA)
111/tcp open  rpcbind 2-4 (RPC #100000)
| rpcinfo:
|   program version   port/proto  service
|   100000  2,3,4        111/tcp  rpcbind
|_  100000  2,3,4        111/udp  rpcbind
1 service unrecognized despite returning data. If you know the service/version, please submit the following fingerprint at https://nmap.org/cgi-bin/submit.cgi?new-service :
SF-Port22-TCP:V=7.40%I=7%D=4/24%Time=5CC040A8%P=arm-unknown-linux-gnueabih
SF:f%r(NULL,29,"SSH-2\.0-OpenSSH_7\.4p1\x20Raspbian-10\+deb9u4\n");

Service detection performed. Please report any incorrect results at https://nmap.org/submit/ .
Nmap done: 1 IP address (1 host up) scanned in 23.12 seconds

/etc/hosts/:

127.0.0.1       localhost
::1             localhost ip6-localhost ip6-loopback
ff02::1         ip6-allnodes
ff02::2         ip6-allrouters

127.0.1.1       juddpi

sudo iptables -L --verbose:

Chain INPUT (policy ACCEPT 0 packets, 0 bytes)
 pkts bytes target     prot opt in     out     source               destination

Chain FORWARD (policy ACCEPT 0 packets, 0 bytes)
 pkts bytes target     prot opt in     out     source               destination

Chain OUTPUT (policy ACCEPT 0 packets, 0 bytes)
 pkts bytes target     prot opt in     out     source               destination

Any help is greatly appreciated.
Thanks, all!