The balloons sink because there is no buoyancy.
The balloons expand because there is more pressure in them because the helium is now trying to get to the less pressurized area.
When the balloons pop the helium does not puddle on the floor of the container.
I'm not disputing buoyancy.
There is no gravity pulling the air down.
In the first video I provided it's showing that the vacuum chamber lost buoyancy.
The live stream I posted in the closed thread gave a presentation on this starting at the 1 hour and 5 minute mark.
I'll repost it after this...
I've never said gas is nothing.
However you have now been shown that taking gas out of a vacuum chamber the chamber gets heavier.
After you falsely asserted that it was not true.
Which shows that you think because you believe something it must be true.