Hello,
in the past the printf came from Stream
- Serial - APIs | Mbed OS 5 Documentation check the tree
- Github- Serial API
In MbedOS 6+ the Stream is not used
- BufferedSerial check the tree
- Github- BufferedSerial API
So, that is right behavior, but exist some workaround.
SerialStream - Bringing MBed serial ports back like it’s 1999…… | Mbed
Hitchhiker’s Guide to Printf in Mbed 6 - Mbed OS - Arm Mbed OS support forum
BR, Jan