Those flickering problems can usually be solved by doing a GPU render using 3d properties on elements (translateZ(0), perspective...).
I have added this CSS code and now it looks pretty fine:
backface-visibility: hidden; /* Chrome */
filter: grayscale(0%); /* FF */
In your case i had to add a filter property for Firefox, i don't know why. Maybe the blur filter you use is the cause of the problem.
Of course this is not a good method to use the universal selector, this code is just a test I've done fastly.