WPC Product Bundles – Possible issue with cached variation image URLs (HTTP instead of HTTPS)

Hi WPC Team,

I recently came across an issue with WPC Product Bundles Premium (8.7.7) where some variation product images were being loaded over HTTP instead of HTTPS, causing broken images due to mixed content.

Interestingly, the issue was resolved simply by opening and updating the variable product linked to the bundle, without making any actual changes.

While investigating the plugin code, I noticed that available variations are cached using WordPress transients for up to 7 days (woosb_avail_vars_). Since WooCommerce's variation data includes image URLs, I suspect that outdated HTTP URLs might have been stored in the cache.

I also noticed that the cache key can include a suffix via the woosb_variations_cache_suffix filter, while the cache invalidation on product updates appears to only delete the transient without the suffix. This could potentially leave some cached variation data intact.

I haven't been able to confirm the exact cause yet, but I thought this was worth reporting in case you've encountered similar issues elsewhere.

Have you seen this behavior before, and could the variation cache potentially explain it?

Best regards,

Niko