Super glad you found and showed us the video, much more context now. And you are indeed bouncing there, a lot. I blame the fins and the way you have set it up, and how your weight and the rigs weight is transferred to the board. Nothing wrong with the board. Note that you are not going particularly fast there, and in all the turns you are sliding, not engaging the rail at all. This is not how pyramids behave, not at all.
Take a look at this. A bit smaller wave, but faster. And see how the board is stable in all turns, rail engaged, and can easily go screaming fast down the line, and always in control.
I'd say, if you set up a board, get it perfectly dialed with the stock fins first, and then, maybe, improve the feel with some other fin setup. That wave in your clip is so smooth. And the speeds are slow. There shouldn't be any bouncing, just smooth sailing. Play with the settings until you get everything in balance and smooth.
One more clip, with a quad, from the same spot. 72 kg and an universal travel board for me, 86 litres. Don't be afraid to put the board on rail, deliberately.
And why not a bit more Pyramid love, while on that topic. And stock fins again of course.