# Sessions decreased since June 9th **URL:** \ **Category:** Data collection and tags\ **Created:** [June 12, 2024, 2:46pm UTC](https://community.piwik.pro/t/sessions-decreased-since-june-9th/4114 "2024-06-12T14:46:43Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![Thomas\_Anode\_FR](https://dub1.discourse-cdn.com/flex005/user_avatar/community.piwik.pro/thomas_anode_fr/32/1425_2.png) [@Thomas\_Anode\_FR](https://community.piwik.pro/u/Thomas_Anode_FR)\ **Post date:** [June 12, 2024, 2:46pm UTC](https://community.piwik.pro/t/sessions-decreased-since-june-9th/4114/1 "2024-06-12T14:46:43Z")
Hello, We noticed a decrease in sessions since June 9th, while nothing was changed in Piwik PRO over this period. No change in the way Piwik PRO is installed too. ![image](https://europe1.discourse-cdn.com/flex005/uploads/piwikpro/original/2X/5/53ae33469e2d84fe2fa6ce0be1c3274784b81636.png) We observe this decrease on the Google Ads traffic, while the Google Ads clicks were quite constant and even went up since June 9th. ![image](https://europe1.discourse-cdn.com/flex005/uploads/piwikpro/original/2X/b/b35761a32f6c1e40178bca563bcf58bb99b6f98f.png) There is always a difference between both tools, and we can usually explain it as clicks are different from sessions. But there seems to be an issue since June 9th. We checked the tracking template and the landing pages in Google Ads, and it’s all good. In comparison, here are the stats from both tools from May 27th to June 8th: Google Ads ![image](https://europe1.discourse-cdn.com/flex005/uploads/piwikpro/original/2X/2/2bb87b533a61db257b6cd4da2769861a709cd78d.png) Piwik PRO ![image](https://europe1.discourse-cdn.com/flex005/uploads/piwikpro/original/2X/a/acbdc82a92017c6b43208535a52a039b53b1ce21.png) As you can see, the charts are quite aligned. Total differences for both periods: - **May 27th - June 8th:** 22,6K clicks for Google Ads, 20,9K sessions for Piwik PRO = 8% gap - **June 9th - June 11th:** 5,4K clicks for Google Ads, 3,4K sessions for Piwik PRO = 37% gap I see changes were made to the tracker on June 4th: [Version 18 - Changelog Piwik PRO](https://changelog.piwik.pro/version-18/). > “We fixed an issue where sessions were split when events had both campaign and referrer parameters, and the campaign parameter was later missing during the session.” Could this explain the decrease? I’ll share the instance in private if needed. Thank you! ---
**Author:** ![Thomas\_Anode\_FR](https://dub1.discourse-cdn.com/flex005/user_avatar/community.piwik.pro/thomas_anode_fr/32/1425_2.png) [@Thomas\_Anode\_FR](https://community.piwik.pro/u/Thomas_Anode_FR)\ **Post date:** [June 13, 2024, 8:35am UTC](https://community.piwik.pro/t/sessions-decreased-since-june-9th/4114/2 "2024-06-13T08:35:09Z")
Update: we are observing this on multiple instances and all traffic sources are impacted. ---
**Author:** ![Admin](https://avatars.discourse-cdn.com/v4/letter/a/3ec8ea/32.png) [@Admin](https://community.piwik.pro/u/Admin)\ **Post date:** [June 13, 2024, 8:42am UTC](https://community.piwik.pro/t/sessions-decreased-since-june-9th/4114/3 "2024-06-13T08:42:35Z")
Hi. Our team is looking into that. ---
**Author:** ![Admin](https://avatars.discourse-cdn.com/v4/letter/a/3ec8ea/32.png) [@Admin](https://community.piwik.pro/u/Admin)\ **Post date:** [June 13, 2024, 8:56am UTC](https://community.piwik.pro/t/sessions-decreased-since-june-9th/4114/4 "2024-06-13T08:56:31Z")
We confirm that there’s an issue with processing the data which affects Core instances that started on the 10th of June. I’ll let you know once the issue is fixed. From that point in time it’ll take a while to reprocess the data for the whole affected period. ---
**Author:** ![Thomas\_Anode\_FR](https://dub1.discourse-cdn.com/flex005/user_avatar/community.piwik.pro/thomas_anode_fr/32/1425_2.png) [@Thomas\_Anode\_FR](https://community.piwik.pro/u/Thomas_Anode_FR)\ **Post date:** [June 13, 2024, 9:02am UTC](https://community.piwik.pro/t/sessions-decreased-since-june-9th/4114/5 "2024-06-13T09:02:08Z")
Thank you Kuba! Great to know that you’ll be able to reprocess the data. 🙂 ---
**Author:** ![Thomas\_Anode\_FR](https://dub1.discourse-cdn.com/flex005/user_avatar/community.piwik.pro/thomas_anode_fr/32/1425_2.png) [@Thomas\_Anode\_FR](https://community.piwik.pro/u/Thomas_Anode_FR)\ **Post date:** [June 13, 2024, 9:39am UTC](https://community.piwik.pro/t/sessions-decreased-since-june-9th/4114/6 "2024-06-13T09:39:34Z")
Are you sure only Core instances are affected? ---
**Author:** ![Admin](https://avatars.discourse-cdn.com/v4/letter/a/3ec8ea/32.png) [@Admin](https://community.piwik.pro/u/Admin)\ **Post date:** [June 13, 2024, 9:41am UTC](https://community.piwik.pro/t/sessions-decreased-since-june-9th/4114/7 "2024-06-13T09:41:38Z")
If there’s ano other instance that might be affected, please send me the URL via private message. ---
**Author:** ![Admin](https://avatars.discourse-cdn.com/v4/letter/a/3ec8ea/32.png) [@Admin](https://community.piwik.pro/u/Admin)\ **Post date:** [June 13, 2024, 10:59am UTC](https://community.piwik.pro/t/sessions-decreased-since-june-9th/4114/8 "2024-06-13T10:59:54Z")
The issue has been resolved for the data collected from now on. I’ll post an update here once the historical data has been reprocessed.