Lectora 11 Publish output inconsistent playback on different computers

We have been developing e-learning courses for many many years now, and more often than not when we publish out content and test the output and track it is recording across various browsers in Standalone and LMS mode we always encounter extremely annoying issues where the content does not consistently produce the same playback experience and outcome (i.e score / completion status) when using the EXACT same browser versions on identical computer setups.

Case in point is a course that was published out of one computer and thoroughly tested on Internet Explorer V10, V9 and Chrome for example and it did not display the Assessments Scores correctly in the popup at the end and yet the debug console clearly indicates the score is tracking correctly via the variables view!! We then go to a separate computer with the exact same published output of the course and run it using the exact same browsers versions and this time it worked correctly!!!

Seriously, how can we possibly trust that the published output is going to work consistently across different computers with the SAME browser versions. The process of testing is becoming extremely tedious to say the least. Has anyone else experienced this or does this just get swept under the carpet and ignored !?