Unknown version in search box doesn't work

[okynos]

Wazuh	Splunk	Rev
4.0.4	8.1.1	68

Description
Never connected agents have unknown version but I cannot search by this field.

Steps to reproduce

1. Go to agents preview
2. Click on search box
3. Select version tag.
4. Set it to unknown (only available if never connected agents are present).
5. See error.

Screenshots

[frankeros]

related issue #1012