So, my fault: It IS actually a kernel issue. I didn't install linux- modules-extra-4.15.0-96-generic package when trying out Ubuntu 18.04 stock kernel on Ubuntu 20.04. After installing this package hcitool lescan works flawlessly...
** Package changed: bluez (Ubuntu) => kernel-package (Ubuntu) -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1870837 Title: hcitool lescan says 'Set scan parameters failed: Input/output error' To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/kernel-package/+bug/1870837/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
