Founded in 1998, San Mateo Studio (formerly Foster City Studio) work out of California as a support studio for other PlayStation first-party developers. They therefore haven't shipped their own PS5 game, nor should you expect them to.
San Mateo Studio did spin off a small team in 2014 called Pixelopus, who released two games before the PS5 launched. However, very low sales and mediocre critical reception resulted in Sony closing the studio down in June 2023.
Due to San Mateo Studio's support status, they haven't shipped a PS5 game where they were the primary developer. In fact, that last game where they were is 2004's Jet Li: Rise to Honor on PS2.
If you're looking for your next first-party PS5 game, you should look elsewhere. If anything, San Mateo are more likely to close if Pixelopus and 2004's Jet Li are any indications.
