When trying to look for queries that start with capital "I", for example "I Can't Believe It's Not Butter!" (no quotation marks) I get the following error from the browser:

This page isn’t working
kagi.com redirected you too many times.

Try deleting your cookies.
ERR_TOO_MANY_REDIRECTS

I tried on different devices, mobile and desktop (but always logged into the same Kagi account). The network tab of the Chrome developer tools show an endless stream of requests to "https://kagi.com/images" even though I wasn't initially searching from the "Images" tab.

If I remove "i" from my Quick Bangs settings the problem disappears, so the problem is clearly connected with this quick bang - but this doesn't explained the endless loop of redirects.

When searching for "I Can't Believe It's Not Butter!", I would expect web search results for "I Can't Believe It's Not Butter!" (because it starts with a capital "I" and not "i") or at the very least image search results for "Can't Believe It's Not Butter!".