I regularly update the custom channel grouping in GA4. As you know, this feature is manually customizable from the admin section, and the results apply to historical data. All reports with the custom channel grouping dimension are affected.
Today, I tried to assign a new source to my organic search, but the channel group didn't change in the reports. I also attempted to create a copy from the default channel group without making any changes, but it didn't work either; all the fields returned "not set." I changed conditions in different time ranges and also in different report tabs. I think this is a GA4 bug and we should wait for a fix
