... Highlight the notes involved, right click, choose properties, and then the Note tab. Note the options for Lyric syllable. By choosing, illustratively, "always", syllables will show up on each tied or slurred note.
Unfortunately, the selection is generic and will apply to all lyrics for that staff.
If you want a lyric syllable to attach to a note, then you should use Steve's approach to have a lyric syllable assigned to that note. You can still skip the note in some lyric lines by using the underscore.