Map has levels where labels don't show within the visible range

[KeithSalmon]

Trial weed map with several visible ranges

For an easier to read version of the following question, please click on this link: 241008 Map has levels where labels don't show within the visible range

1. Low level range with labels: This map under development has three levels of labels in the layer “Target Species in a Weed Control Area” The screenshot shows the map zoomed in so it is inside the top of the LOW LEVEL visible range for the scale label: “Small building”  - with labels showing against the points. We have tried to set the Zoom Levels for each of the 3 labels so that they touch each other but don’t overlap. We are having some trouble with this.
2. Top of low level range with NO labels: Clicking on the Zoom out button once, the screenshot shows the map zoomed in so it is just inside the top of the LOW LEVEL visible range where the upper level has the scale label  small building with a custom level of 1:809.  The current map view is 1:564 However the defined labels are not appearing.
3. Bottom of mid level range with labels: Clicking on the Zoom out button once, the screenshot shows the map zoomed so it is just inside the top of the MIDLEVEL visible range where the upper level has the scale label  Street and the lower level has the scale label Building with a custom level of 1:801. And the current map view is 1:1128
The same problem occurs when one transitions from the Mid to the High Level - where the level is in both the Mid and High Level (which is why the name of the weed looks to be bolded - as it is repeated in the label for both levels). The upper bound of the Mid Level is: 1:7450 And the lower bound of the High Level is: 1:7900

There appear to be some data adjustment rules as one amends the Custom level.  Sometimes if you move it up or down, it will change the name of the scale label from eg Streets to Street - even though it is midway between the nominal ratio (aka “representative fraction”) for each level.

I found this via CoPilot - it seems to confirm what I assume is the case - however, it doesn’t tell me at what RF value, AGOL will swap the scale label. Nor does it explain why there are gaps where the labels don’t appear even if the current map view is within the visible range.

Copilot Sent by Copilot: In ArcGIS Online (AGOL), the scale label changes based on the representative fraction (RF) you set. Here’s how it works: Representative Fraction (RF): The RF is a ratio that represents the scale of the map. For example, an RF of 1:10,000 means that 1 unit on the map equals 10,000 units in the real world. Visible Range: When you set the visible range for labels, you can specify the RF directly. This determines the zoom levels at which the labels will appear. For instance, setting a visible range from 1:5,000 to 1:50,000 means labels will be visible when the.... Scale-Based Label Sizing: AGOL allows you to adjust label sizes based on the scale. This means you can set different font sizes for different RF values to ensure labels are readable at.... Predefined Zoom Levels: You can also choose predefined zoom levels instead of manually entering RF values. These predefined levels correspond to common map scales, making it easier to set consistent visible .... By understanding and adjusting these settings, you can control how and when labels appear on your map, ensuring they are clear and informative at different scales.

If someone could point me to these rules, I’d be grateful.

[RussRoberts]

We do have a known issue in the JS Maps SDK where we are working on resolving some issues with scale level and label classes not always displayed as expected. You can track it with BUG-000167329