Cannot use keybase.txt file

I have half a dozen domains, all hosted through the same 1&1 host.

2 of the domains I was able to successfully verify with a /keybase.txt file. However, the other ones all required that I use /.well-known/keybase.txt and refused to verify with the file in the root directory.

The only difference I could see in how the two domains that worked might have operated is that they had a .htaccess file, but that was only configured to redirect non-existent pages and keep anything that was there. Otherwise, identical. Headers and responses looked the same, but I could not get them to accept.

I can reproduce the issue consistently, but have no idea if the issue is on keybase.io's end or that of my host. Any advice would be welcome.

Start by comparing the affected domains' responses for /keybase.txt and /.well-known/keybase.txt, including the .htaccess behavior described in the report. Reproduce the verification failure and determine whether the discrepancy comes from Keybase's verification or the 1&1 hosting configuration; document the cause and any required change.

Written by the indexing model from the issue text.