Real world story: 2020/01 I was investigating why the PCP grafana vector plugin does not work for me. Component wise, PCP is running, the PCP grafana plugin, and grafana providing the service. PCP PMDA bcc is installed and reading kernel data, which gets illustrated by grafana. A browser accesses the grafana service. I was running the whole PCP/grafana parts in a virtual system, and prepared reproducer instructions so colleagues would install RHEL8.2beta, setup the services - but then their result was different, for them the vector plugin was working. A colleague logged into the virtual guest, forwarded the grafana service which did not work for me - and for him the service did work. Then I realized that the browser used for the access was part of the observation.. and sure enough with a different browser the access worked - and also with firefox after disabling the ublock adblock/trackerblocker plugin.