Unable to filter the issues when label is being used

[sv-calin]

*Edit: Not reproducible while logged in

Url: https://webcompat.com/issues

Environment: Operating system: Windows 10 Firefox version: Nightly 104.0a1 (2022-07-14) (64-bit)

Steps to reproduce:

1. Go to https://webcompat.com/issues
2. Type a label in the search bar (eg. "label:engine-gecko")
3. Press "Enter"
4. Click on "Newest"
5. Pick a different filter
6. Observe the result

Expected Behavior: Issue filtering is possible.

Actual Behavior: Filtering is not possible, an error is displayed on top of the page.

Notes:

1. Screenshot provided: https://prnt.sc/8CrTqUufMJYp
2. Reproducible in Chrome as well
3. Pressing back returns the same error
4. Refreshing the page shows no results and a message is displayed " Sorry, no results were found. "
5. Reproducible with other labels and filters
6. Not reproducible while logged in

Watchers: @softvision-oana-arbuzov @softvision-raul-bucata @ClintNase