Mysteriously I could not connect via ssh from my Manjaro client (converted Macbook Pro 13’ 2009 to Manjaro linux rolling release lean machine) to any ssh server if I was connected over wifi !?! IF however I am connected via a network cable all worked without problems!
I first though it’s not me (you know… linux) must be external forces at play!
I research that-research this … but no solution. The next modem I encountered the same problem appeared and so on and so on…
I was a hard realization but it slowly sank into my brain I should first look at myself?
So again … searched and searched till I finally found my rescuing sentence on the arch wiki [no link sorry forum policy]!
which states: “SSH freeze for BCM4331 with b43: The b43-firmware driver has been observed hanging in ssh sessions with BCM4331. Installing broadcom-wl and removing b43 solves it.”
So by installing linux512-broadcom-wl (as I use kernel 5.12) and remove the b43-fwcutter core firmware I was finally able to solve this annoying mysterious problem and could finally connect to any ssh server with a distance greater than the length of my network cable 
Hope this can help anyone out there as this post would have helped me for sure!
Happy exploring!