The discovery page now shows 2 columns with "Zabbix agent: system.uname":

1. Zabbix agent: system.uname
2. Zabbix agent(0): system.uname

It seems that somehow the system.uname is duplicate but I can't say when this happened. I recently updatd to version 3.4.6 but can't tell for sure if this issue is related to that upgrade.
As per the attached screenshot, the 2 duplicate columns sometime have different value, sometime have the same value, but I cannot identify a pattern.