HTMLViewer Full screen unavailable Mac Mojave


I have an a Xojo 2018 Release 4 project that has an HTMLViewer that I compiled on MacOS Mojave Version 10.14.3.

I am almost sure that in a previous version of MacOS, maybe 10.12 that I could get “Full screen”, but with this new Xojo/Macos configuration that is unavailable.

I saw other posts on the forum but none of them mentions/addresses my issue.

How can I fix that?