Problem with identifying traffic sources in analytics systems

After installing Cloudflare on my sites, I observe problems with determining the sources of traffic to the sites. The problem is that the bulk of visitors are now defined as “Internal (Referal) Traffic” (75%), although 95-99% of traffic is traffic from search engines. I am also not sure about the correctness of the data received regarding the general statistics of visits. This problem is observed both in Google Analytics and in Yandex.Metrica.

Yandex.Metrica technical support indicated that the problem is in putting the address of the login page in the referrer, thereby getting an internal transition (screenshot).

Is it possible to fix this problem on the Cloudflare side?

Thanks. Daniel.