Your one-sheet can hold eight testimonials. The page only ever shows three.
The proof section stores more than it displays, and the gap is not a bug. Here is what Speaker Hub actually caps in your one-sheet's proof row, and how to use the extra room on purpose.

Open the proof section of your one-sheet editor and you can add up to eight testimonials. Publish the page and only three of them show up. That is not a rendering bug you stumbled into. It is a deliberate gap between what you are allowed to store and what a planner is shown, and most speakers never notice it because they never fill more than two or three slots to begin with.
Three is what a planner reads. Eight is your bench.
The sheet itself only has room for three testimonials before it starts crowding out the sections that actually get you booked: your flagship talk, your topics, your stats. So the page draws your three strongest and stops there.
The storage cap sits well above that, at eight, and the reason is not generosity for its own sake. Speaker Hub's After Talk tool writes audience quotes straight into that same testimonial list after an event wraps, without going through the same checks the editor's save button does. If the storage cap matched the display cap of three, the next time you hit save in the editor, anything past the third quote would get silently cut, including whatever After Talk just added. Capping storage at eight instead of three leaves room to keep collecting without losing what just came in.
