I had a problem where i couldn’t send files from my CachyOS desktop to my Android phone. After searching the forums i found that one user resolved a similar issue by manually installing SSHFS and this also worked for me. I’m wondering whether SSHFS is a missing dependency in the KDEconnect package?
That sounds correct, SSHFS should be a dependency of the package for the kdeconnect-kde project. Best to open an issue report for the package in CachyOS 