So I posted this question in the DM's Only forum, thinking I'd misunderstood something, and apparently I hadn't but Maps is working incorrectly.

Example 1:

Single Level 5 Character.

XP Budgets:

• Low: 500xp
• Moderate: 750xp
• High: 1100xp

Using Animated Armor as the example, CR 1, 200XP units, the Map responds with:

• 1-3 Armor (200-600xp) - Low.
• 4-5 Armor (800-1000xp) - Moderate
• 6+ Armor (1200xp+) - High

From my understanding, the XP budgets are 'up-to'.  As in when you exceed a threshold, you're going into the next tier. All examples followed this. While I don't see the point of High having an XP value, except as something to aim for, aren't these brackets still wrong?

I would have expected:

• 1-2 Armor (200-400xp) - Low.  Does not exceed 500xp.
• 3 Armor (600xp) - Moderate. Above 500xp, and does not exceed 750xp.
• 4+ Armor (800xp+) - High.  Above 750xp, with a preference to use 5 armor (1000xp) for a High encounter as the closest without exceeding.

Example 2:

Doing the same with 4 Level 5 characters:

XP Budgets:

• Low: 2000xp
• Moderate: 3000xp
• High: 4400xp

Using Animated Armor as the example, 200XP units, the Map responds with:

• 1-14 Armor (200-2800xp) - Low.(breaks the 2000xp budget)
• 15-21 Armor (3000-4200xp) - Moderate (breaks the 3000xp budget as a starting point)
• 22+ Armor (4400xp+) - High (Starts at the High budget)

Midway breakpoints for this would be 2500xp and 3700xp which doesn't fit with this either.

Using a CR5, 1800xp Hill Giant:

• 1 Hill Giant (1800xp) - Low
• 2 Hill Giants (3600xp) - Moderate (Breaks the 3000xp budget)
• 3 Hill Giants (5400xp) - High

Example 3:

With 4 level 5 characters again, I added 300 10xp Rats.  At 2990xp (299 rats) it is considered Low.  At 3000xp (the maximum budget for Moderate) it becomes Moderate.  I did not add more Rats as 305 tokens makes the Map a bit unstable, but the point is clear.

Bug:

It appears that the Maps encounter difficulty calculator is using the maximum budget as a minimum value.  So when the budget is below the Moderate maximum, it's Low, when it's Moderate maximum up to just below High maximum, it's Moderate, and anything High maximum or up is High. 

This is the opposite of the declared method in the Dungeon Master's Guide, and thus the Maps encounter difficulty calculator is incorrect.

Quote from spamandtuna >>

It’s using the rules from the 2014 DMG, not the 2024 one.

The Maps tool specifically uses 2024 according to all information.

Balancing Your Encounters

At the bottom of the Combat Encounter menu, you’ll see the difficulty rating of the encounter based on the encounter balancing rules in the 2024 Dungeon Master’s Guide. With this, you’ll always have an idea of how challenging your encounter is going to be.

https://www.dndbeyond.com/posts/1841-roll-for-initiative-combat-tracking-comes-to-the

Are you saying that all of these are incorrect?

Quote from spamandtuna >>

No, that’s mistake. Sorry. I thought we were talking about Encounters, not Maps.

I’d recommend uaing the feedback link inside Maps itself for any Maps feedback. That way it will go directly to the Maps team and they can investigate any issues.

 
I did do that, but pointed the feedback to this thread, as the explanation is too long to fit in the short Feedback window.

One month in, another Maps update (13th) and still an issue.

Another update and still the Encounter Difficulty calculator is broken as described.  I have reported this in the Maps Feedback through the tool and referenced this thread because the explanation is too big to fit in the Feedback window.