Comment 5 for bug 1821729

Bisection led me to the following fix:
 https://github.com/tianocore/edk2/commit/272658b9971865812f70e494d0198f13df8b841b

I've uploaded test kernels to a PPA, can you verify that the 18.04 ('bionic') one fixes the problem for you?
  https://launchpad.net/~dannf/+archive/ubuntu/test