Hello,
I have the same problem. I using SB2 with all the latest updates, an updated dock, Microsoft USB keyboard and mouse with Microsoft Mouse and Keyboard Center. I tried uninstalling and reinstalling the drivers and no difference. The keyboard is also affected sometimes I'll be typing and I'll get something like " " or "ffffffffffffffffffffffffffff" show up right after the lag spike.
Is there a solution for this yet?
So I had been using my SB2 on 1709 undocked for several months because I was traveling and had a bad experience trying to upgrade to 1803 (thankfully was able to revert to a restore point). My touch pad started freezing especially when two finger scrolling in August. Now I am done traveling, updated to 1803 and the latest firmware, and its unbelievable how Microsoft can make things worse and worse with each update. I too am having issues when docked on my external keyboard having a lag/spike and getting a "ffffffffffffffffffffff" and my computer seems slow and laggy a lot of the time and fan running full blast. These weren't issues before I updated and I wish I hadn't. I have been watching my PC performance and am never really using more than half the RAM/CPU. I don't know why it gets laggy then. Even after closing all open applications, the SB2 was still laggy and fan running full speed. A reboot solved the issue for now. Good grief Microsoft.