RPi Wireless SSH Problems

Hy guys,

I have some problems to ssh into my RPi (3 B+ with Ubuntu Mate). My goal would be to ssh from my laptop into my RPi wireless.

When I use the ethernet cable I do not have problems, it connects immediately. On the other hand, when I try to ssh via wireless network, I have almost every time problems, e.g: the laptop does not even "see" the RPi when I look for it with nmap (or any other command). Then there is something weird: when I connect the RPi on a monitor I can ssh wireless. What could be the problem?


are laptop and pi on the same subnet?

They should. I connected my RPi only to one network, so I don't understand why it doesn't connect to the network when I boot without the screen.