update:
I just connected to machine “remote” on 10.10.10.180 with the following command:
nmap -A -T4 -p- 10.10.10.180.
Tried a couple of others which I couldn’t connect to (it seems).
Then I tried “remote” again and it wouldn’t connect!
And as we speak I’m scanning “remote” AGAIN, and now it works.
I’m really clueless what this could be.