After some more investigation I found out that the software I am using is NOT using hcitool. It really seems to be another problem since the custom software and the hcitool lescan command are throwing the same error observed with btmon:
@ RAW Close: hcitool {0x0004} 20:16:29.633716 @ RAW Open: hcitool (privileged) version 2.22 {0x0004} [hci0] 20:16:29.633742 < HCI Command: LE Set Scan Parameters (0x08|0x000b) plen 7 #35 [hci0] 20:16:29.633780 Type: Active (0x01) Interval: 10.000 msec (0x0010) Window: 10.000 msec (0x0010) Own address type: Public (0x00) Filter policy: Accept all advertisement (0x00) > HCI Event: Command Complete (0x0e) plen 4 > #36 [hci0] > 20:16:29.750680 LE Set Scan Parameters (0x08|0x000b) ncmd 1 Status: Command Disallowed (0x0c) @ RAW Close: hcitool Software (phython): @ RAW Open: python (privileged) version 2.22 {0x0003} [hci0] 20:14:38.006713 > HCI Event: Command Complete (0x0e) plen 4 > #28 [hci0] > 20:14:38.119126 LE Set Scan Enable (0x08|0x000c) ncmd 1 Status: Command Disallowed (0x0c) < HCI Command: LE Set Scan Parameters (0x08|0x000b) plen 7 #29 [hci0] 20:14:38.119219 Type: Passive (0x00) Interval: 10.000 msec (0x0010) Window: 10.000 msec (0x0010) Own address type: Public (0x00) Filter policy: Accept all advertisement (0x00) > HCI Event: Command Complete (0x0e) plen 4 > #30 [hci0] > 20:14:38.119989 LE Set Scan Parameters (0x08|0x000b) ncmd 1 Status: Command Disallowed (0x0c) < HCI Command: LE Set Scan Parameters (0x08|0x000b) plen 7 #31 [hci0] 20:14:38.120063 Type: Passive (0x00) Interval: 10.000 msec (0x0010) Window: 10.000 msec (0x0010) Own address type: Public (0x00) Filter policy: Accept all advertisement (0x00) > HCI Event: Command Complete (0x0e) plen 4 > #32 [hci0] > 20:14:38.120946 LE Set Scan Parameters (0x08|0x000b) ncmd 1 Status: Command Disallowed (0x0c) < HCI Command: LE Set Scan Enable (0x08|0x000c) plen 2 #33 [hci0] 20:14:38.120988 Scanning: Enabled (0x01) Filter duplicates: Disabled (0x00) > HCI Event: Command Complete (0x0e) plen 4 > #34 [hci0] > 20:14:38.121945 LE Set Scan Enable (0x08|0x000c) ncmd 1 Status: Command Disallowed (0x0c) -- 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/bluez/+bug/1870837/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs