Problem with melisma not appearing/displaying

Hi there,

When i am adding lyircs and create a melisma after a word until the end of the bar or even further using the shortcut "SHIFT Underscore", the cursor moves the next postion/note each time however the melisma fails to appear. I presume this is a bug as it was working earlier in my project then just stopped working and i have tested it on many devices. Please may you suggest ways to fix this/work around this.

I have attached a snip of my score, the melisma fails to continue after "trol"