After we created GA4 Properties I noticed an error in comparison to UA. IN GA4 we now have more than double the amount of direct traffic in our session default channel grouping. What is even more strange is that the overall traffic is nearly identical between GA4 and UA. So I assume there ist a shift in traffic probably from the google ads traffic (because they now have significant less traffic) to the direct traffic.
Till now I have just tried to find the mistake in the GTM but I found nothing
It is a GA4 bug, Paid search events are incorrectly attributed to Organic traffic and/or Direct traffic.
Here an open issue tracker: https://issuetracker.google.com/issues/241258655