Graph drag loses priority to box select after shift depress

[rayment]

When using the left mouse button to drag the graph after previously holding shift to perform a box select, the shift depress is not detected and the mouse remains in a select state rather than the default drag state.

It is hard for me to reproduce as it occurs sporadically, but I have managed to capture the result of the bug:

I have turned screenkey on, and as you can see, it is not until I press and depress shift again that the mouse can drag the graph again.

Steps to reproduce:

1. Create some nodes in the graph.
2. Hold shift and select a node or two, then depress it. It sometimes helps to have a checkbox or a button and press it while the nodes are selected - (probably placebo).
3. Observe that sometimes, the mouse remains in a select state and does not drag the graph when the left mouse button is held down.

This bug occurs on Linux for version 3.0.8 (other versions untested). So far I cannot reproduce it on Windows.

Environment:

OS	Qt	Compiler
Gentoo Linux, kernel 6.1.4	5.15.7	gcc 11.3.1