There is a new bug introduced in v3.13.0 involving plots and the default selection tool.
When opening an already created plot, the "rectangle" is typically selected and works as expected in a new plot. When selecting the "freeform line", it also works as expected in a new plot. The trouble comes when the plot is closed and re-opened after which the same tool (whether it be line or rectangle) is selected but the selection mode is always "rectangle-like." The way it worked in v3.12.0 is that the previously selected tool would remain selected after re-opening a plot. This is helpful when switching views and plots being able to be selected a certain way (the same way) after switching views.
I've attached a YouTube video from both Hog 4 PC and a Hog 4 console illustrating the issue. The same issue occurs on an actual Hog 4 console in the same way. The Hog 4 PC show is a brand-new showfile while the Hog 4 video is of a preexisting show updated from v3.12.0.
Hog 4 PC v3.13.0 Plot Selection Bug Report - YouTube
Hog 4 Console v3.13.0 Plot Selection Bug Report - YouTube