I unlocked the report again (so I could move items around inside the table cells) and moved the Hyperlink into the TicketNo Column. (make sure you select the inner box in the hyperlink when dragging):
And achieved a usable result in PDF:
The final issue was, I only want to see the Hyperlink. Seeing the TicketNo and the TicketNo named hyperlink together seemed redundant. I clicked inside the TicketNo item's Table Cell and selected 'Box Type' -> 'None'.
This hid the TicketNo field, but its Grouping is still in effect:
The result in PDF was exactly what I was looking for:
The Hyperlink appears to be grouped on!