Why do you have 4VPP output and the LNA on!? Is the SA fried already? Please, delete the misleading video if you didn't use attenuators...
Come again' misleading

When you're working with any SA.. its your job to know the limits of your device and honor those, and since I don't show the cabled input as it had no relevance, and the focus was on aligning the two screens, and lower the lightsensitivity a lot' so both screens were readable.
It doesn't take a Ph.d to conclude the use of an attenuator in such a situation, which is a good rule of thumb, when working with any signal generator directly connected to a spectrum analyzer that tends to have quite limited front-end protection.
The video has nothing to do with SA4's limits, it's solely a display of the modulation-ability that is still valid on DG821PRO with the UI bug, when in arb while maxed at 200MHz.
You are allowed to use common sense, and it's literally printed on the unit and also highlighted to the moon & back for each of these units, which exact tolerances they can safely handle
https://tinysa.org/wiki/pmwiki.php?n=TinySA4.ComparisonYou can clearly sense there is a metal shining barrel element before the socket of the SA4 in the vid above.. if you took a wild guess, could that be an attenuator?
You can see the written text on the unit's enclosure and its limits below. I wear both belt & braces when first dealing with a cheap MAX2870-based signal generator from the Szhenchen flea market.
But in general, when you connect a spectrum analyzer to any signal device that got a variable output that can go above your SAs tolerances, it's good practice to have an attenuator inline.
(2023) were unsure where the signals [10.49G & 11.55G] originated from..