Why does bluetooth suddenly not work anymore?

I have a Lenovo Thinkpad T460p with Ubuntu 20.04. Everything was fine yesterday, but today bluetooth stopped working. I didn't even shutdown. No system updates as far as I remember.

$ blueman-manager
blueman-manager version 2.1.2 starting
blueman-manager 09.01.28 ERROR    Manager:118 on_dbus_name_appeared: Default adapter not found, trying first available.
blueman-manager 09.01.28 ERROR    Manager:122 on_dbus_name_appeared: No adapter(s) found, exiting

$ hcitool scan
Device is not available: No such device

$ sudo dmidecode -s bios-version
R07ET63W (2.03 )

$ sudo dmidecode -s bios-release-date
03/15/2016

$ dmesg | grep -i blue
[    3.091649] Bluetooth: Core ver 2.22
[    3.091666] Bluetooth: HCI device and connection manager initialized
[    3.091669] Bluetooth: HCI socket layer initialized
[    3.091671] Bluetooth: L2CAP socket layer initialized
[    3.091674] Bluetooth: SCO socket layer initialized
[    3.136626] thinkpad_acpi: rfkill switch tpacpi_bluetooth_sw: radio is unblocked
[    3.140252] Bluetooth: hci0: Bootloader revision 0.0 build 2 week 52 2014
[    3.149664] Bluetooth: hci0: Device revision is 5
[    3.149665] Bluetooth: hci0: Secure boot is enabled
[    3.149665] Bluetooth: hci0: OTP lock is enabled
[    3.149666] Bluetooth: hci0: API lock is enabled
[    3.149667] Bluetooth: hci0: Debug lock is disabled
[    3.149668] Bluetooth: hci0: Minimum firmware build 1 week 10 2014
[    3.153992] Bluetooth: hci0: Found device firmware: intel/ibt-11-5.sfi
[    4.224885] Bluetooth: BNEP (Ethernet Emulation) ver 1.3
[    4.224886] Bluetooth: BNEP filters: protocol multicast
[    4.224889] Bluetooth: BNEP socket layer initialized
[    4.664148] Bluetooth: hci0: Failed to send firmware data (-38)

Did the chip just break? Could I confirm that?

edit: I've just found a USB bluetooth adapter. When I plug that one in, it works again. So I guess it must be a part of the hardware that broke?

I've just remembered that it might be a weird Fn-Key combination that might have disabled bluetooth. I went through them and accidentially enabled airplane mode after bluetooth broke. Then I switched Wifi + Bluetooth back on and it works again. I have no clue what happened, but I guess Bluetooth was just disabled by software.