How do I enable OpenGL Impress Transitions?

I’m running Linux Mint 19.1 (based on Ubuntu 18.04) with the Cinnamon desktop.

I’ve installed LibreOffice 6.2.2 through the official Ubuntu PPA.

All works fine, except OpenGL transitions on Impress slides. The non-OpenGL transitions work perfectly, but when I select an OpenGL transition, the slide goes blank for a couple seconds, then the slide image appears again without having done any sort of transition preview, and the slide sorter on the left shows that a transition was not added to the slide. And occasionally when I select an OpenGL transition, LibreOffice crashes.

I have Hardware Acceleration turned on. I do not see any options for whether or not to use OpenGL, like I had in the past.

Any suggestions?