we have just deployed and released copr-frontend-1.129. This package contains the latest fixes upon big work done in copr-frontend-1.128. Also new python-copr-1.87 was released with a fix in ClientV2 regarding build statuses ("forked", "waiting") that were recently added into copr-frontend and ClientV2 became out of sync.
You can find the latest packages at https://copr.fedorainfracloud.org/coprs/g/copr/copr/
(dnf copr enable @copr/copr + dnf install <coprpkg>) if you are too impatient to wait for the Fedora package to get into stable :).