Just noticed on 6.11b2 that there are gaps when dragging across text to highlight it. I do this a lot and haven't seen this anomaly before.
I can reproduce this on Windows 10
I see the same on Win 7. Not a big issue, but somewhat distracting.
Thank you for reporting this, I can reproduce this on both Mac and Windows. I have submitted a case for us to get this resolved.
This is now fixed in 6.12.