Some control characters not repeating anymore in the matlab editor

I use the emacs emulator mode in the MATLAB editor. Starting with R2018b, some control characters don't repeat any more. For example, the first time I hit CTRL-k it works fine, but if I hit it a second time in a row then I get the letter k instead. I have to release the CTRL key once before I can do a second CTRL-k. This behavior only effects certain control characters (e.g. CTRL-n, CTRL-f and CTRL-p repeat just fine) in the editor.

This behavior only shows up in Matlab on this system (Linux: Centos 7). Other applications that use control characters work as expected. For example, in a regular emacs session (outside of Matlab) CTRL-k repeats just fine.

This started happening when I upgraded to R2018b, but I also did an OS upgrade at the same time so not sure which of those it triggered this behavior.

This is not happening to me on my matlab 2018b installed on other platforms (e.g. CTRL-k repeats just fine on my R2018b instance on my Mac).

Anyone else see something similar? Any known fixes?