Now I am having the same issue, not only with interactive render... the render did stop when the stop button was pressed, but the start button was not enabled, and the stop button is still active for selection, as if it was still running and we still had to confirm we want the process to stop, the stats say it stopped, but I cannot start again unless I close and reopen Archicad. Just opening and closing the Corona windows ( either one ) won't re-enable the start button, the process remains frozen until Archicad is re-initiated.
Not sure what is causing, but now I am testing a project I already had which has a good density of lights and transparent materials ( a sort of glass house ). I want to spend some time today constructing a simpler model just to test these issues later ( as well as study Archicad -> Blender transitions, as so far I am having problems with UVW texturing on Blender from Archicad models... but it doesn't make sense to remodel things again ).
I am running Archicad 22 Solo Build 4024 INT on a Core i7 4720, 16GB memory, nVidia 980M GTX Board With 4Gb VRAM Driver 416.34