Okay I confirmed all of that and it seems like the guest user is working okay.

Let's begin with this data point which no longer updates:

member2BoilerStatusCode

The data flows as follows:

device -> via ModbusRTU to MangoES -> via Publisher to Enterprise Mango.

• ModbusRTU to MangoES: data is successfully retrieved

• Publisher to Enteprise Mango: data has not updated since 2/7/2016

I really wish I could attach images on here but you guys have some problems with IMGUR apparently, anyway.

• MangoES: Data updates correctly visible on the watch list, it is not disabled.
• MangoES Publisher: member2BoilerStatusCode shows up on the "Published data points"

I tried removing it and re-adding it to the publisher and that did not help.
I even tried changing the data point template to update when timestamp changes and that did not resolve it.

I don't see any problems with the history synchronization otherwise in the publisher status or events.

I'm not sure how to diagnose this.

It sounds like your diagnosis is on the right track. Here are the most likely causes based on what you’ve described:

1. Check that the guest user actually has the Users role
   Since the point shows Users = checked and Anonymous = unchecked, the guest account must:

• Be successfully logged in
• Belong to the Users role

If the guest account was created manually rather than through the usual user-creation workflow, it’s possible it never received that role.
You can verify under Administration → Users → guest.

2. Confirm whether auto‑login is actually succeeding
   If your auto‑login fails silently, Mango will treat the session as Anonymous, and any point that does not allow Anonymous access will simply disappear with no warning.
   To verify:

• Open your dashboard URL in a private/incognito window
• Check whether Mango shows you logged in as guest

Also, your example URL uses:
autoLoginPassword=guest1234

But you mentioned the password is guest. If those don’t match, the login will fail and the session becomes anonymous.

3. For meta points specifically

• Meta data points inherit visibility from their own permissions, but their values come from underlying source points.
• If the guest user does not have permission to read one of the source points a meta point depends on, the meta point may appear on the dashboard but will fail to resolve a value.
• So make sure the source points also include the Users role (or whatever group your guest belongs to).

4. Version change (5.6.2 → 5.6.3)

• Since this was working before the upgrade, it’s worth checking the 5.6.3 release notes. There have been a few changes recently around role evaluation and anonymous access. Even subtle permission tweaks could affect dashboards that rely on auto‑login.
  https://docs-v5.radixiot.com/v5-release-notes-overview