Content impressions and page-views show up from different IPs (and are therefore recognised as different users)

Nobody has claimed this yet.

We recently implemented the tracker-proxy and everything looks good, except:

Our Matomo is running as a docker container behind a reverse proxy. I think this might be the issue, but I do not know how to proceed. The initial configuration was:
```
[...]
proxy_client_headers[] = "HTTP_X_FORWARDED_FOR"
proxy_host_headers[] = "HTTP_X_FORWARDED_HOST"
[...]
```

After a little try-and-error now we are running this and it "feels" a little better, but I can not say for sure. This is also does not happen to every tracked user:
```
[...]
; following line was added to test split users
; It is also possible to check multiple proxy_client_headers, which will be checked in order until a header value is found:
proxy_client_headers[] = "HTTP_CLIENT_IP"
proxy_client_headers[] = "HTTP_CF_CONNECTING_IP"
proxy_client_headers[] = "HTTP_X_FORWARDED_FOR"
proxy_host_headers[] = "HTTP_X_FORWARDED_HOST"
[...]
```

We are on the most current versions (Matomo version: 5.3.2, tracker-proxy Commit 942980e).

I am open any hint or suggestion. Please also ask if you need more information about our setup.

The issue names no repository file or test. Start by reviewing the shown proxy_client_headers and proxy_host_headers settings alongside the reverse-proxy setup, then compare client-IP values for affected requests. Done means identifying a reproducible cause and documenting or implementing a configuration fix that consistently recognises the same user.

Written by the indexing model from the issue text.