I don't think that's anything specific to tallow. It could be partly because the oil wasn't hot enough (or was cooled by attempting to fry too much at once). In terms of frying, there's a tiny miniscule difference between grain-fed and grass-fed beef tallow (and grain-fed, with less polyunsaturated fatty acids, actually comes out as slightly better for high-temperature frying).
But most likely, it's just an inevitable result of cooling fried food. While food is being fried, the water is being evaporated and so the constant steam pressure stops oil from sticking to the food. But as soon as the food drops below the boiling point of water (or if you overfry the food so that all the water is lost), the oil starts to be absorbed. Blotting quickly with paper reduces how much oil is left to be absorbed, but realistically there's nothing you can do. Just fry enough that you can eat while they're hot.
"Thanks to the combination of meat, calcium-rich leaf foods, and a vigorous life, the early hunter-gatherers were robust, with strong skeletons, jaws, and teeth." - Harold McGee, On Food And Cooking: The Science and Lore of the Kitchen