Why This Happens
When you switch or publish a new theme, certain customizations don't carry over because they're stored in the theme itself, not in the app.
What Carries Over vs What Doesn't
Setting | Carries Over? | Where It's Stored |
Bundle configuration (products, pricing, etc.) | ✅ Yes | MOD Bundles app |
Custom CSS in MOD Bundles → Customization | ✅ Yes | MOD Bundles app |
App block positions | ❌ No | Theme |
App block settings | ❌ No | Theme |
Custom CSS in theme editor | ❌ No | Theme |
Custom Liquid sections | ❌ No | Theme |
What You Need to Redo
After switching themes:
1. Re-add App Blocks
Go to Online Store → Themes → Edit theme
Navigate to your product template
Click Add block → Apps
Add the appropriate bundle block:
Mix & Match Bundle Pack Builder Collection BundlePosition the block where you want it
Click Save
2. Reconfigure App Block Settings
In the theme customizer, click your bundle app block and check:
Bundle Product (only for page/collection templates)
Any theme-specific settings in the block
3. Re-add Theme-Specific CSS
If you had CSS in the theme editor (not in MOD Bundles):
Go to Online Store → Themes → Edit code
Add your CSS back to the appropriate file
Preventing Future Issues
Save Your Custom CSS
Before switching themes:
Copy any custom CSS from the theme editor
Save it in a text file
Apply it to the new theme after switching
Use MOD Bundles for CSS (Recommended)
CSS added in MOD Bundles → Customization → Custom CSS persists across theme changes.
Go to MOD Bundles app
Click Customization
Add your CSS in the Custom CSS field
Save
This CSS applies to all themes and won't be lost when switching.
Document Your Setup
Keep a record of:
Which templates you use for bundles
Where you positioned app blocks
Any custom settings you applied
Switching Between Multiple Themes
If you frequently switch between themes (e.g., seasonal themes):
Set up bundles in each theme you use
Save the theme with bundle blocks configured
When you switch, bundles will work if already set up
Common Scenarios
"My bundles stopped showing"
After a theme switch, bundles won't show until you add the app blocks to the new theme. See Bundle Not Showing on Storefront.
"My custom styling is gone"
Check if your CSS was in the theme editor or in MOD Bundles:
Theme editor CSS → needs to be re-added
MOD Bundles CSS → should still be there
"I can't find my bundle product"
Your bundle products still exist! Go to Products in Shopify admin to find them. The bundles are intact; only the theme display needs to be reconfigured.