I have create new AWS instance and defined connection to it via PAC manager. Later I realized that pasting through middle mouse button click or pasting through context menu is incredibly slow. Almost like typing it on keyboard. Pasting through CTRL+INSERT was fast.
I suffered two days with it and did not succeed in googling that issue. Today I found out that problem was in “Wait 200 millisecs for automated char sending” setting. In rest of connections it is set to 0 so I have no idea how this setting was done – maybe I set it by incident.