Comment 35 for bug 1818134

Other commenters, please confirm what kernel version you are seeing this behavior with. If this is not reproducible with either the linux-generic 3.13 kernel or the linux-lts-xenial 4.4 kernel, then it is not going to be fixed.

Note also that Ubuntu 14.04 has reached the end of standard support, so in addition to the other *-lts-* kernels being out of security support for a long time already, the rest of your system is also out of security support unless you have ESM enabled.