I am not able to reproduce this. Can you provide more information?:
Printer Profile Chosen:
Printer Model: Canon PRO-100
Driver Version: 1.6.20
Printer Profile Chosen: Custom printer profile
I have identical hardware/OS installed but do not use any Custom Print Profiles. To eliminate that, can you try saving or creating with a standard print profile and see if it sticks?
I cannot duplicate still after watching your video. Have you attempted a Preference File reset?
Close Lightroom: Hold down [Alt]+[Shift] and launch Lightroom again. Overwrite the preferences when prompted.
Attempt to duplicate. What happens?
I reset the LR preference and the problem is still present.
Since I cannot reproduce what you have demonstrated Frank, my recommendation is going to be to do an uninstall/reinstall of Lightroom. If the problem did indeed occur upon installation of CC2015.6, then I am leaning toward a problem with the installation. Backup your catalog JIC. Use your Creative Cloud app to remove Lightroom (your catalog and preferences will remain intact). Reboot. Install Lightroom CC2015.6 from the Creative Cloud App.