Custom Variable #4 being replaced with Search Category (1 reply)

I couldn't find any documentation to support or help troubleshoot this behavior, or even acknowledge it, but as I say in the title I am seeing my fourth Custom Variable being replaced by a provided Search Category. Here is the code snippet:

_paq.push(['setCustomVariable', '1', 'name1', 'value1', 'page']);
_paq.push(['setCustomVariable', '2', 'name2', 'value2', 'page']);
_paq.push(['setCustomVariable', '3', 'name3', 'value3', 'page']);
_paq.push(['setCustomVariable', '4', 'name4', 'value4', 'page']);
_paq.push(['setCustomVariable', '5', 'name5', 'value5', 'page']);
			
_paq.push(['trackSiteSearch', "Sample Search Term", "Category - Sample", false]);

The request out to piwik shows the cvars to be consistent with the custom variables I have set:

{"1":["name1","value1"],"2":["name2","value2"],"3":["name3","value3"],"4":["name4","value4"],"5":["name5","value5"]}

Yet when I look at the visitor log, the custom variables appear as follows (formatted for visibility)

Custom Variables 
- name1 = value1
- name2 = value2
- name3 = value3
- Search Category  = Category - Sample
- name5 = value5

Is there any reason for this, or some documentation I could take a look at? I'd appreciate any help anyone could extend regarding this behavior.

Thanks,
-Ben VonDerHaar