I just updated to Lectora 19.0.3 from 18.2.3. I have a Skip to Content transparent button as my first object in the title explorer (after two actions).
In 18.2.3, when I hit Tab, the Skip to Content transparent button would highlight. In 19.0.3, when I hit tab, it does not highlight but will work.
I turned on NVDA to make sure it is the first object found and it is. It is read like it is supposed to.
The only thing I changed was to set it Always on Top because a breadcrumb box does overlay the Skip to Content transparent button. That had no effect. I tried shortening the breadcrumb box, and that did not make a difference.
I’m sorry to hear the fix did not work for you. If you care to share your title, I can post a link for upload and take a look. The fix for this problem should be in v19.1 which is due out in September.