I believe I’ve figured it out. Something has changed in the usb layer, which is preventing the stick from being allocated properly.
I did some more searching, but what I’m hitting appears to be a linux usb bug, specifically xhci_hcd where the front usb ports (secondary hub) are not registering devices properly.
In syslog I found xhci_hcd messages that indicated the stick could not be allocated.
Jul 28 13:24:24 bernzie kernel: [ 4.149310] xhci_hcd 0000:00:14.0: xHCI Host Controller
Jul 28 13:24:24 bernzie kernel: [ 4.219497] xhci_hcd 0000:00:14.0: new USB bus registered, assigned bus number 2
Jul 28 13:24:24 bernzie kernel: [ 4.321573] usb usb1-port3: couldn’t allocate usb_device
$ lsusb -tv
/: Bus 02.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/6p, 5000M
ID 1d6b:0003 Linux Foundation 3.0 root hub
/: Bus 01.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/7p, 480M
ID 1d6b:0002 Linux Foundation 2.0 root hub
Simply moving the stick to the rear USB port allowed it to be found and my system when back to normal.
$ lsusb -tv
/: Bus 02.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/6p, 5000M
ID 1d6b:0003 Linux Foundation 3.0 root hub
/: Bus 01.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/7p, 480M
ID 1d6b:0002 Linux Foundation 2.0 root hub
|__ Port 2: Dev 3, If 0, Class=Communications, Driver=cdc_acm, 12M
ID 0658:0200 Sigma Designs, Inc. Aeotec Z-Stick Gen5 (ZW090) - UZB
|__ Port 2: Dev 3, If 1, Class=CDC Data, Driver=cdc_acm, 12M
ID 0658:0200 Sigma Designs, Inc. Aeotec Z-Stick Gen5 (ZW090) - UZB
|__ Port 5: Dev 2, If 0, Class=Wireless, Driver=btusb, 12M
ID 8087:07dc Intel Corp.
|__ Port 5: Dev 2, If 1, Class=Wireless, Driver=btusb, 12M
ID 8087:07dc Intel Corp.
More research is required, but I’m good for now.
Maybe this will help someone else.
Cheers!