It's not a compound adjective, it's an adjective modified by an adverb. The relevant rule in the lesson is:

5. Adjectives modified by adverbs with 2 or more syllables

Adjectives usually go AFTER nouns (adjective position)

Adjectives with complements such as, e.g., facile à faire,  are treated as one compound adjective and come after the noun.

What specifically is your problem?

hi chris

every time i get to those questions i seem to get the adjectives placement wrong even though i know it's the right order but, also if there is an adjective plus the adverb i seem to get that wrong.

Can you post a few examples and how you get them wrong? It would help me find a better answer to your question.

OKay so for these 2 sentences the first one I got wrong

Un étonnamment bon film. I know that bon goes before the now but why is it marked wrong?

Then the other sentence un clown extrêmemment drôle I know that drôle is describing the clown and how sorry he is but I got that right but now the other sentence?

Thanks 

Nicold

This link might be helpful: https://www.lawlessfrench.com/grammar/compound-noun-plurals/

hi chris,

I am already aware of this site and the link you sent but it doesn't help my question though. For one of the examples listed for number 4 it says adjectives followed by a complement ( a de pour comme) so the one example sentence is un exercice facile a faire but on one of the quizzes that i took i had chosen un etonnamment bon film but they said it was wrong. 

i know in english it means surprisgnly so would etonnament be used as an adverb to be place after the adjective good?

thanks chris i really do appreciate your help

If I understand you correctly, you're uncertain about which of the two versions is correct:

un étonnement bon film vs. un film étonnement bon.

My understanding is that the compound adjective (étonnement bon) is treated as a whole new adjective and therefore placed in the default location, i.e., after the noun.

Maybe this question needs to be re-posted again to bring it to the attention of one of the kwiziq native speakers?

Thankyou, chris for your help.

Yes, but that doesn’t shed any light on Nicole‘s question either. 

It explains why you say "un bon film", but "un film étonnement bon". I thought that was the question.