Google Analytics reports drop on sessions, increase on avg session duration after setting up referral exclusion list and filters

Question

My sessions dropped around 65% and my session duration increased ~60%, after adding a subdomain (aa.​example.com) to the Referral Exclusion List and setting some filters. This changed happened on 24th February and on 25th the dropped happened. I rollback everything on 27th but it's still down compared to what was before.

I also lowered the session and campaign timeouts to 1 hour.

What has changed?

1. I added a new view to the GA for a subdomain ​​​aa.example.com ​(before I only had a view for ​www.example.com.​) Then I added the following filters:

   View 1: www.example.com -> exclude (hostname) aa.example.com

   View 2: aa.example.com -> include (hostname) aa.example.com

2. Added aa.example.com to the Referral Exclusion List (there was nothing there before)

It seems that there is a relation between the increase of the duration of sessions and the drop of sessions. However, I have no idea why, since the filters and the Referral Exclusion List are rollback, the traffic is not going back to normal. I'm using Cloudflare and there is no change in terms of traffic there.

Does anyone have any ideas what's causing this issue?

Thanks

Answer 1

I found the issue! It was related to some scripts from admanager that were giving an error on loading and consequently not triggering an event on google analytics.

In the end, it was not related to Referral Exclusion List neither filters.