Version 8.5 for Mac pasting last commands on left mouse click

[ofmanyone]

I have SecureCRT 8.5 installed on Mac OS 10.14.6. It's behaving in a way that I've never seen before. When I click on the terminal window, with the standard left click, it pasts the last command I typed. If I click again, it pastes the previous command that I typed, as if it's interpreting my left-click as an up arrow (to scroll through previous commands). This is driving me insane . Please help me figure out how to disable this. Thanks!