Global BPDUguard disabling interface without portfast.

So correct me if I'm wrong, but I was under the impression that BPDUguard only gets enforced on interfaces that have portfast configured.

I have a Sonos device that was not coming up because the port was going err-disable (Sonos uses STP, who knew?). BPDUguard is globally enabled, portfast was enabled on the port:

Global:

spanning-tree portfast bpduguard default 

Interface:

interface GigabitEthernet1/0/6 description Sonos switchport access vlan 20 switchport mode access spanning-tree portfast 

I thought that removing "spanning-tree portfast would bring the interface up just fine, however the switch was still placing the interface in err disable even after removing this line.

I had to use "spanning-tree bpduguard disable" to get the interface up.

Am I misremembering how BPDUguard works? I'm reading the official Cisco documentation that says:

Spanning tree shuts down STP ports that are in a Port Fast-operational state if any BPDU is received on those ports.

What am I missing?