English equivalent for new Brazilian Portuguese slang term “desaplaudido”?

There is no direct English translation, but since it's such a new word in Brazilian Portuguese slang, perhaps we'll see a similar slang word emerge in English!

I agree with the suggestion made by @Tom22 that buffoon is probably one of the closest English words that describes something similar, although it's not nearly as descriptive as desaplaudido.

We have the noun try hard

A person who puts a large amount of effort into achieving a certain image, or counter-image, to the point where it is obviously contrived. Rather than achieving an image through genuine personality, the try-hard consciously attempts to fit a certain style through deliberate imitation, forced style, or scripted behavior. That is to say, he/she is trying hard to create an image.

Examples:
An affluent, suburban dweller who makes great efforts to cover himself in tattoos and piercings; try-hard.

A person who wears certain items of clothing for the express intention of appearing "non-conformist", and flaunts it; try-hard.

Someone who purchases a motorcycle only to appear as a "bad-boy"; try-hard.

https://www.urbandictionary.com/define.php?term=try-hard