I just upgraded my Mac Pro from 10.13.6 to 10.14.6 and found there was a severe display performance degradation, if running on a 5K display under 10bit color depth mode.
In 10.13, Alfred always shows the expected results in almost zero latency, but since the OS upgrade to 10.14.6, there is always a delay of 100ms-200ms before the icons of the results are shown.
After some efforts, I found the performance impact is due to the color depth of the display. If I use the default color profile (Dell 2715K, 10-bit color), the problem can always be reproduced. If I switch to "sRGB I