I am trying to create a Lightning Web Component that I can put on the standard Account page and have a custom toast message displayed every time the page is edited.   The LWC would not have any UI.  It would be hidden and respond to the record update event from the standard page.
I was able to do something similar with aura using this example: http://www.sfdcpanda.com/custom-user-message-in-standard-lightning-page/
But this example didn't work quite right.  It only seemed to fire when you edited the page through the edit button.  If you edited a field by clicking the pencil on the field it didn't fire the event.
So I am trying to do the equivalent with LWC in hopes that it will work correctly from either edit method.
Any help would be appreciated.

We have a Napili based community (with custom lightning components) in a sandbox (DEV) with url = https://dev.cs21.force.com
We created another community in another sandbox and migratated everything over (DEMO).
The new sandbox url = https://demo.cs21.force.com/membership
(NOTE the community in DEMO now has "/membership" as part of the url.

We have a button on a custom lightning component that calls javascript that calls a visualforce page to initiate a docusign envelope creation.
The javascript uses window.open.
In DEV the url we call = "/apex/dsfs__DocuSign_CreateEnvelope?DSEID=0&SourceID=..."
(NOTE - This works perfectly in DEV)

The same javascript url does not work in DEMO.
In DEMO I had to change the url to -
url = "/membership/apex/dsfs__DocuSign_CreateEnvelope?DSEID=0&SourceID=..."

Any idea why I had to add the /membership to the /apex url?

Thanks in advance.

I am trying to create a Lightning Web Component that I can put on the standard Account page and have a custom toast message displayed every time the page is edited.   The LWC would not have any UI.  It would be hidden and respond to the record update event from the standard page.
I was able to do something similar with aura using this example: http://www.sfdcpanda.com/custom-user-message-in-standard-lightning-page/
But this example didn't work quite right.  It only seemed to fire when you edited the page through the edit button.  If you edited a field by clicking the pencil on the field it didn't fire the event.
So I am trying to do the equivalent with LWC in hopes that it will work correctly from either edit method.
Any help would be appreciated.