@mms @stefano this sounds like normal first level support behavior. When at customer projects I hit the wall with permission/groups I end up screen sharing with 1th level support. They make me install Putty when they see I use the OpenSSH client directly. For them it's the only way to ensure the behavior in their instructions is replicated correctly, despite technical details provided or infos like "my colleague has group XY, but not my user - just add me to it.".

Support usually works with tutorial videos, some cheat sheets with screenshots or, likely in your case, just an SSH banners handed out to them.

This is not the support's fault, but rather how they are organized. Management works with numbers and the cheapest way is to outsource it to a different country with unqualified personnel that costs them pennies. They measure how many tickets they close on the dollar, but not the time You spend on the problems. Broken metrics.