It’s not an issue with Visualarq at all. The grasshopper boolean commands in general seem to be very sensitive and have a lot of issues with plane orientation, unit tolerances, and overlapping surfaces. I often see comments in the forum where folks are having issues.
If it were a one-off script we could just go in there and fix the issue, but with a grasshopper style you wouldn’t want to go edit the script. If possible, I just avoid the boolean commands and create the element another way. However, I’m not an expert level grasshopper user.