Se sentir et aller

Question

I know that se sentir and aller identical. But in this exercise it does not work.

Franck________ en pleine forme.

Answer: se sent

Franck va en pleine forme. It is false. I wonder why it is incorrect?

Accepted Answer

They are not identical. They have enough overlap in meaning in some situations in French that they may be used with nearly identical meaning, and translated as such in English - but not all.

Answer

I have seen in related topic like that:"In this context, se sentir is identical in meaning to aller."

Answer

I think that is the point 'in this context'. That does not mean in all contexts:  https://progress.lawlessfrench.com/revision/grammar/how-to-express-how-you-are-with-the-verb-aller-greetings. The 2 lessons combined confirm that it is a substitute (se sentir with aller) with an adverb, but not with adjectives (or an adjectival phrase) - an alternative then is to use être and indeed «Je suis en pleine forme» is used.

Answer

Merci beaucoup ! When i hit the "explain this" button, i cant find the answer in related topic sometimes. Thanks for the link also.