That’s because the PLACE devices are listed through ETL (Intertek) instead of UL. Here’s the record in Intertek’s directory for the smoke alarm (UL 217) side – they also have an ETL UL2034 listing for their CO functionality, and the Kitchen model (PL1K) is listed as a fuel gas alarm too (via ETL, to UL 1484).
Also, AFAICT, they can function as a “dumb” hardwired smoke/CO alarm without WiFi or the use of the “smart” app.