Sometimes the radicals may not look exactly the same as in the kanji, but I try to deal with it. After all, the radicals are there to help you remind what the kanji most looks like. Good luck!

You could say that, kind of.. But it really is just one radical, written slighly different when in different kanjis. Also it depends on fonts too. And honestly if you’re learning kanji through Textfugu, keep in mind that he sometimes makes things up, radical wise, in a way that I assume he thinks makes it easier to learn the kanji. Sometimes making up radicals that don’t officially exist and ignoring ones that do. I often find that the radicals he says are in a kanji don’t match when u compare to sites like denshi jisho. But since it gets you to learn the kanji, often easier because he picks things that make more sense, I can’t say I mind too much.

The kanji radicals from another Japanese resource may not be the same as the kanji radicals from Textfugu, but when searching for kanji in Jisho, some of the radicals may be the same, and those may possibly help for searching for kanji.
Sometimes the radical in a kanji doesn’t look exactly like the actual radical – one way to deal with this may be to create a ‘mini-story’ about the part that corresponds to why the radical looks different. For example, in the kanji 図 which means ‘diagram’, it is made up of the Narwhal, Ice, and Mouth. But to me the Narwhal don’t exactly look perfect. Maybe the Narwhal is sleeping, so that’s why it looks a bit bended. And perhaps the ice is on the ceiling of the mouth-like cave.
Maybe for 上 one could say that the the toe was straightened because of the ‘wea’ther (うえ) or something like that.