Comment 22 for bug 1886277

$ sudo apt build-dep linux
$ git clone git://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/bionic
$ cd linux
$ git bisect start
$ git bisect good Ubuntu-5.4.0-39.43
$ git bisect bad Ubuntu-5.4.0-40.44
$ fakeroot debian/rules do_dkms_nvidia=false do_dkms_vbox=false do_dkms_wireguard=false do_tools=false do_zfs=false no_dumpfile=1 skipabi=true skipconfig=true skipdbg=true skipmodule=true skipretpoline=true clean prepare-generic binary-headers binary-generic
Install the newly built kernel, then reboot with it.
If it still have the same issue,
$ git bisect bad
Otherwise,
$ git bisect good
Repeat to "make -j`nproc` deb-pkg" until you find the offending commit.