With --no-configs it is working properly.
I had a nnoremap d dd but I did delete it from vifmrc before reporting the problem.
Interestingly, if I try :nmap dd with a --no-configs instance, I get a single line saying
dd remove files
However, if I try the same in a normal instance, I get an empty line before that.
{empty line}
dd remove files
I have no idea of what is causing this, but it must then be in my vifmrc. I'll keep trying to track down the issue. Thank you for your help.