We recently completed a major installation of ArcGIS Enterprise 11.3 for a client, which included a complete data migration into their new system. Utilizing ArcGIS Pro, we published layers from their database directly to their new portal. Everything was set up for a seamless experience—until an unexpected issue emerged.

The Alignment Issue

After deploying the webmap in an Experience Builder application, our team noticed that the map layers were not aligning correctly with the basemap. Here’s what we observed:

Consistently Inconsistent: Despite verifying projections and coordinate systems, every republish of the map layers resulted in misalignment in the ArcGIS Portal webmap. The fiber network feature seemed to ‘hop’ around the map space.
Conflicting Results Across Devices:
- The client’s computer exhibited persistent alignment issues.
- Interestingly, when we accessed the portal on our systems, as well as on an iPad or another user’s computer, the map data aligned perfectly.

This inconsistency was perplexing and demanded deeper investigation.

The Debugging Journey

We began by rechecking every variable that could influence map rendering:

Revalidating Projections and Coordinate Systems:
We double-checked all spatial references, confirming that there were no discrepancies that could cause the misalignment.
Republishing Multiple Times:
Despite several attempts and republishing sessions, the misalignment persisted on the client’s main system.
Browser and Cache Considerations:
We had the client try different browsers and even cleared browser caches—none of which resolved the issue.
A Surprising Discovery with Developer Tools:
The breakthrough came when we noticed that opening Chrome Developer Tools seemed to “correct” the alignment. This was a critical hint that the issue might be related to the browser’s rendering dimensions.

The Root Cause: Screen Resolution and Size Limits

Digging deeper, we discovered that the primary client’s workstation featured a 49" wide screen with a resolution of 4216 x 976 pixels. When the browser window was resized (as it often is when opening Developer Tools), the map data would align properly.

After thorough testing, we pinpointed the issue to a specific limitation: the Experience Builder application’s map element appears to have a maximum width limit for properly displaying a mapping service. Our tests revealed that:

A Webmap element set to 3280 pixels would not align correctly.
Once we reduced the width to 3275 pixels, the map aligned perfectly.

This finding confirmed that the Experience Builder webmap element has a hard limit of 3275 pixels. Exceeding this limit can lead to unexpected rendering issues like the one we experienced. This is our experience, your results may vary.

Lessons

Screen Resolution Matters:
Large monitors and high-resolution screens can expose limitations in web application design that might not be apparent on standard displays.

Dynamic Testing Can Reveal Hidden Issues:
Simple actions like opening Developer Tools, which resize the browser window, can provide clues about underlying layout constraints.
Set Explicit Limits:
When designing applications in Experience Builder, consider setting maximum element widths to prevent layout issues across different devices and screen sizes.
Document Your Findings:
Sharing insights like these can help other developers avoid similar pitfalls and contribute to a more robust design for web mapping applications. We’re all swimming the dark, your discovery may open the door for someone else.

While our initial installation and data migration were successful, the misalignment issue provided an opportunity to dive deep into the nuances of Experience Builder’s rendering behavior. Understanding that a pixel limit of 3275 exists for the webmap element not only helped resolve our client’s issue but also highlighted the importance of considering display dimensions during application design.