Host seems down

Hi there!
I’ve just subscribed for HTB and tried some Machines to earn points, but I keep getting “Host seems down” while I’m doing Nmap scans.
I’ve tried “Keeper” and “Codify” machines and both gave me this error (I watched walkthrough for one of them and this error is not supposed to be there).
I’ve got VIP+ and trying to do it with PWNBox.
Are there any solutions for this?
Thanks in advance!