Before I post something on git, wanted to check here. I have tested this on our self-hosted version of KoBo ( 2.020.28a ) as well as kc.kobotoolbox.org and the same issue arises.
In “Data” tab under “Table” view, I can search/filter using all fields except “_uuid”. Using this field causes a server error and returns/displays something like < h1> Server Error </ h1> in the table view section of the page. A project I support was using this to search for submissions (they temporarily are moving to use _id at my suggestion) and they noticed a few months ago that it stopped working. Apparently it used to work and maybe stopped with an update to KoBo? As I never used it myself I never saw it actually work in the first place. Should filtering via _uuid be possible and/or did it break at some point in the switch to two-databases?