Unable to get Bluetooth to work on main with CSR5810

For years I have been trying to get Bluetooth to work on my Lenovo T16
AlderLake laptop.It came with a AX201 WiFi/Bluetooth interface and I was
pleased when iBluetooth was supported, but didn't work, so I spent $7 on a
CRS5810 which is claimed to work well on FreeBSD. Unfortunately, I still
see the same problem so I now assume that the problem is me.

When I insert the CSR I get:
ubt1: <vendor 0x0a12 CSR8510 A10, class 224/1, rev 2.00/88.91, addr 4> on
usbus1

This is almost exactly what I see at boot on the AX201.  According to
Handbook, I should see something like this:

ubt0: vendor 0x0a12 product 0x0001, rev 1.10/5.25, addr 2
ubt0: Interface 0 endpoints: interrupt=0x81, bulk-in=0x82, bulk-out=0x2
ubt0: Interface 1 (alt.config 5) endpoints: isoc-in=0x83, isoc-out=0x3,
      wMaxPacketSize=49, nframes=6, buffer size=294

usbconfig shows:
ugen1.4: <Bluetooth Dongle (HCI mode) Cambridge Silicon Radio, Ltd>
at usbus1, cfg=0 md=HOST spd=FULL (12Mbps) pwr=ON (100mA)

I tried starting it, but it fails with /etc/rc.d/bluetooth: ERROR:
Unable to setup Bluetooth stack
for device ubt1

Can anyone suggest what probably obvious thing I might be missing? I'd
really love to
be able to use my earbuds on this system.

-- 
Kevin Oberman, Part time kid herder and retired Network Engineer
E-mail: rkoberman@gmail.com
PGP Fingerprint: D03FB98AFA78E3B78C1694B318AB39EF1B055683