My company uses pybleno to initialize bluetooth LE devices on our IOT devices as GATT servers. This has worked fine from 4.x kernels on Ubuntu 18.04 up to 6.5.0 on Ubuntu 22.04 for us. The Python code interfaces with the socket.c userland functions AFAICT. After upgrading from 6.5 to 6.8 kernel on Ubuntu 22.04, the kernel is now returning "[Errno 22] Invalid Argument" from the socket.c setsockopt function. I have outline as best I can what I checked in the downstream pybleno ticket here: https://github.com/Adam-Langley/pybleno/issues/63 I could use some input on whether on not any of the recent socket.c changes between 6.5 to 6.8 changes could have caused this and if this is a regression or whether not the Python calls to these socket.c functions which have worked since 4.x need to be rewritten as a result of an expected interface change on the kernel side. This problem exists for us as well when we tested with mainline 6.9 and 6.10 kernels last week and our only current solution is downgrading to 6.5 . Thank you,