Manjaro stopped to bother with Deepin and we simply sync the packages from Arch directly. Most work into making it kinda work is done by @felixonmars from Archlinux. More or less the latest packages from Deepin upstream get packaged by him.
Deepin is focusing on their distro for now, as that is what they get paid for. Having to deal with the pressure of the Chinese government to get their OS ready makes almost no room to listen to the wider community using their FOSS product. Correct me if I’m wrong, but all that gives almost no free time for them to fix bugs reported by us.