Founded in 1998, San Mateo Studio (formerly Foster City Studio) work out of California as a support studio for other PlayStation first-party developers - particularly neighboring California-based studios like Naughty Dog and Insomniac. They therefore haven't shipped their own PS5 game and you shouldn't expect them to.
San Mateo Studio did spin off a small team in 2014 called Pixelopus, who released 2 games before the PS5 launched. However, despite many award nominations for their second game (2019's Concrete Genie), very low sales, mediocre reviews, and their more AA singleplayer DNA resulted in Sony closing the studio down in June 2023, during the midst of their live-service push.
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 they traditionally developed was 2004's Jet Li: Rise to Honor on PS2. An action-adventure that only scored 68 on Metacritc.
If you're looking for your next first-party PS5 game, you should look elsewhere. If anything, San Mateo Studio are more likely to close if Pixelopus and 2004's Jet Li are any indications.
