Wanna try something for shits n' grins?...
Get your body water under control as needed, drop your carbs for about 24 hrs and go back in slightly dehydrated (e.g., don't drink anything after 5-6PM the night before if you're doing a morning test with them) and see what they come up with for BF%.
The fun part could be the Q and A / explanation you get as to why you're so much fatter now...
That's a bioelectrical impedence machine they used, so it has underlying assumptions based on the hydration and impedance (resistance) to current flow of the fat-free mass (FFM). Increased water retention, from storing it along with glycogen (e.g., especially going from a depleted to supersaturated state), from eating a ton food along with water, especially with plenty of sodium, from estrogen-related water retention, or what have, you changes the hydration of the body. The underlying assumption of the method is that the FFM is more hydrated than the Fat Mass, which is true. (The computational equations used by the machine are usually not available, as these are proprietary info. Sometimes you can't even get the company to tell you how they came up with them. I looked briefly at the site, but didn't find anything.)
So, if you gained water weight during the cycle, the BIA will, based on its underlying software, interpret this as an increase in FFM, which means a decrease in Fat Mass (according to the BIA), so you end up with a calculation of less BF and thus a lower BF% estimate.
Years ago, I screwed around with one of these (experimental model) and would after a weekly carb-up that added bout 10lb of bodyweight (from keto to fullblown nasty carb and sodium and water - it was Rebound Training, which you can google), I'd gain in about 12-15lb of "FFM" in just 24hr and lose about 3-5lb of "fat," if I recall. I was amazed at what 2 trips to the AYCE buffet and piles of homemade pancakes could do for body composition... LOL
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Either way, that's a pretty high BF% (even if the estimate is quite high) to be starting a bulking cycle, so I can imagine you feel like ass now... (I would...)
-Scott