Common issues and solutions for HubSpot CMS, including performance problems and tracking issues.

HubSpot Troubleshooting Overview

This section covers common issues you might encounter with HubSpot CMS Hub, including performance problems, tracking issues, and platform-specific challenges.

Common Issue Categories

Performance Issues

HubSpot sites can experience performance problems affecting Core Web Vitals and user experience.

Largest Contentful Paint (LCP)

Slow loading times
Large images blocking render
HubSpot modules loading slowly
External scripts delaying content
CDN not optimized

Cumulative Layout Shift (CLS)

Content jumping during page load
HubSpot forms shifting layout
Dynamic Smart Content causing shifts
Images without dimensions
Custom modules with unstable layouts

Tracking & Analytics Issues

Problems with GA4, GTM, Meta Pixel, or HubSpot's native analytics.

Events Not Firing

GA4 or Meta Pixel events not tracking
Form submissions not captured
GTM tags not firing
Duplicate events
HubSpot analytics conflicts

Quick Diagnostic Steps

Performance Issues

Test with PageSpeed Insights
- Visit PageSpeed Insights
- Enter your HubSpot URL
- Review Core Web Vitals scores
- Identify specific issues
Check HubSpot Page Performance
- Go to Website → Pages
- Select page
- Click Actions → View page analytics
- Review load times
Inspect Browser DevTools
- Open DevTools (F12)
- Go to Network tab
- Reload page
- Identify slow resources

Tracking Issues

Verify Base Installation
- Check Site Header HTML contains tracking code
- Verify no JavaScript errors in console
- Confirm tracking IDs are correct
Use Browser Extensions
- Google Tag Assistant - For GTM debugging
- Meta Pixel Helper - For Meta Pixel verification
- GA Debugger - For Google Analytics
Check HubSpot Analytics
- Go to Reports → Analytics Tools
- Verify HubSpot tracking is working
- Compare with external analytics

HubSpot-Specific Challenges

Native Analytics Conflicts

Issue: HubSpot's built-in analytics may conflict with external tools (GA4, etc.)

Symptoms:

Duplicate event tracking
Discrepancies in numbers between platforms
Form submissions counted multiple times

Solution:

Accept both systems track events (they serve different purposes)
Use HubSpot for CRM and contact attribution
Use GA4 for website behavior and user flow
Document which system is source of truth for each metric

See Analytics Conflicts for details.

HubL Variable Issues

Issue: HubL variables returning empty or incorrect values

Symptoms:

\{\{ contact.email \}\} returns empty string
Template variables undefined
Conditional logic not working

Solutions:

Check variable scope - Contact variables only work for identified visitors
Verify syntax - HubL is case-sensitive
Test with static content first
Check required modules - Some features require specific HubSpot subscriptions

Debug:

{# Test variable output #}
Contact Email: {{ contact.email }}
Contact ID: {{ contact.vid }}
Lifecycle: {{ contact.lifecycle_stage }}

Template and Module Issues

Issue: Custom modules or templates not working as expected

Common problems:

Module not appearing on page
HubL syntax errors
Module fields not populating
Template inheritance issues

Solutions:

Check module fields - Verify field IDs match template references
Review template structure - Ensure proper HubL syntax
Clear cache - HubSpot caches templates and modules
Check console - JavaScript errors may prevent module loading

Form Tracking Issues

Issue: HubSpot forms not triggering external analytics events

Causes:

Event listener added after form loads
Incorrect form callback syntax
Multiple form implementations conflicting

Solution:

// Proper form event listener
window.addEventListener('message', function(event) {
  if (event.data.type === 'hsFormCallback' && event.data.eventName === 'onFormSubmitted') {
    // Your tracking code here
    console.log('Form submitted:', event.data.id);
  }
});

See Form Tracking.

Debugging Tools

Browser Developer Tools

Console:

View JavaScript errors
Test HubL variable output
Debug event firing

Network Tab:

Monitor resource loading
Check tracking pixel requests
Identify slow scripts

Performance Tab:

Record page load
Identify render-blocking resources
Measure Core Web Vitals

HubSpot Developer Tools

Template Inspector:

In HubSpot, add ?hs_preview=true to URL
View template structure
See module rendering

HubL Playground:

Test HubL syntax
Debug variables
Experiment with logic

External Tools

PageSpeed Insights:

https://pagespeed.web.dev/
Core Web Vitals analysis
Performance recommendations

GTM Preview Mode:

Debug tag firing
Inspect data layer
Test triggers

GA4 DebugView:

Real-time event inspection
Parameter verification
Event debugging

Getting Help

HubSpot Support

HubSpot Academy - Free training and certification
HubSpot Community - Forum for peer support
HubSpot Support - Technical support (varies by subscription)
HubSpot Documentation - Official guides

External Resources

Stack Overflow - hubspot tag for technical questions
HubSpot Developer Slack - Community for developers
This Documentation - Platform-specific guides

Prevention Best Practices

Performance

Optimize images before uploading to HubSpot
Use HubSpot's CDN for asset delivery
Minimize custom code in modules
Async load scripts when possible
Test on staging before production changes

Tracking

Use GTM for centralized tag management
Document all tracking implementations
Test in preview mode before publishing
Use descriptive names for tags and triggers
Version control GTM containers

Development

Use Design Tools for local development
Follow HubL best practices from HubSpot docs
Test across browsers and devices
Implement error handling in custom code
Keep modules simple and focused

Next Steps

Choose your issue category:

Fix LCP Issues - Improve page load speed
Fix CLS Issues - Reduce layout shifts
Fix Events Not Firing - Debug tracking problems

For integration-specific issues, see the Integrations section.