Plato
Plato's name is practically synonymous with philosophy and it would be strange if the falsafa owed nothing to the ideas of Aristotle's master. This presence, practically obligatory when we talk about philosophy, is certainly verified when we come into contact with many of the ideas of Arabic-speaking philosophers.
However, Plato's presence in the falsafa was built up more through the influence of Platonic and Neoplatonic texts than through a direct exegesis of his books by Arabic philosophers, unlike what was done with Aristotle.
In this sense, Plato's writings don't seem to have caught the attention of Arabic-speaking philosophers as much as Aristotle's philosophy. Plato's life and his role in the history of Greek philosophy were well known, but full translations of his works did not have the same presence as in the case of Aristotle.
Initially, Plato's main dialogues began to be translated, but then they stopped abruptly, in favor of paraphrases and summaries of his main ideas. At the same time, numerous apocryphal texts erroneously attributed to Plato were translated.
In the case of the Republic, we know, through Averroes, that there was an Arabic translation that he paraphrased. The paraphrase prepared by Averroes has come down to us preserved in a Hebrew translation.