I have SecureCRT 8.1.4 (old, I know) installed on a 2018 15-inch MacBook Pro running Mojave. I get random slowdowns when changing back to an active SecureCRT window and have since I first installed the application. There doesn't have to be an active connection for me to see the slowdown which makes me think its the application and not a connection. There's also no obvious pattern except that it lags only when switching back to the SecureCRT application from other windows but once the lag is done I don't have any more problems while SecureCRT is the active window. I can switch back and forth to other applications for hours and all of a sudden switching back to SecureCRT I get the slowdown again. This is the only application I ever have slow down like this. When it happens it's like the mouse gets stuck clicked down as well. Sometimes it'll start dragging a session out of session manager, other times it'll highlight random text until I click again or anything else you can think of that could happen by clicking and dragging the mouse, but it always takes 5-10 seconds of the beachball before I see the application act like it's caught up and start the mouse drag. After it has caught up and I click elsewhere to 'unstick' the mouse it works fine. This happens with multiple different mice and the trackpad so I don't think it's the mouse I'm using and it doesn't happen in other applications.
Any ideas on how I can fix this? Is this a known bug? There was something similar listed as a fix in the Windows SecureCRT 8.5 changelog but I didn't see anything like this listed for Mac. I also have SecureCRT installed on a Windows 10 machine and have no problems with it.