Hi, i don’t know this distro, but linux. Try to install a tool like top, glances and atop highlight problems. Open a terminal run glances or atop and reproduce your issue. Glances or atop should help you.
Often, lags are caused by missing graphics driver or win managers running in a compatibility mode.
Cinnamon. Whenever I try something different I always come back. Stable, reliable, similar to Windows, but without all the unnecessary improvements.