Aeon Multisensor 6 with Firmware 1.08 Won't include

I have been in the thick of a major upgrade (10 yr old Mac mini / python 2) to M1 Mac mini / Python 3. Down to the last coupe issues!

I have multiple Aeon multi sensor 6 (ZW100) and I have successfully excluded and re-included them with encryption in my z-wave network, except for one unit. All other units have Aeon Firmware 1.12 and are now working fine.

The trouble unit has Aeon firmware 1.08 and per the Aeon website docs on firmware updates it warns not to update units with firmware 1.08 because that is "old" hardware and new firmware will brick them. This unit was also working fine prior to my major upgrade project.

The Issue:
This unit successfully excludes. Then we trying to include with encryption, I get this in the log:

Jun 1, 2023 at 22:59:15
Z-Wave Syncing - started for "107 - Multilevel Sensor (routing)"
Z-Wave Syncing - retrieved module neighbors list: 1, 8, 33, 38, 39, 40, 41, 54, 85, 86, 90
Z-Wave Syncing - assigning return route to "107 - Multilevel Sensor (routing)"
Z-Wave Syncing - assigned return route
Z-Wave Syncing - retrieved manufacture and model names: Aeon Labs - 0086, Multi Sensor 6 (ZW100) - 01020064
Z-Wave Syncing - retrieved protocol version 4.05, app version 1.08
Z-Wave Syncing - retrieved class hierarchy: Routing Slave : Multilevel Sensor : Multilevel Sensor (routing) (04 : 21 : 01, base 31)
Z-Wave Syncing - retrieved command classes: 20v1 31v5 5Ev1 86v1 72v1 59v1 85v1 73v1 71v1 84v2 80v1 30v1 70v1 7Av1 5Av1 98v1
Z-Wave Syncing - retrieved encrypt commands: 5E 86 72 84 59 85 73 71 80 30 31 70 98 7A
Z-Wave Syncing - retrieved capabilities: routing, battery, beaming, security, waking
Z-Wave Syncing - retrieved wake interval of 60 minutes
Z-Wave Syncing - device "107 - Multilevel Sensor (routing)" wake interval changed to 60 minutes

Jun 1, 2023 at 22:59:38
Z-Wave Error Syncing - failed
Z-Wave Error Timeout waiting for "107 - Multilevel Sensor (routing)". Module might be asleep, or is unreachable.

I have tried about 10 times with the same result. Seems like it's almost complete, but gets stuck on reading/writing parameters? ...there should be a bunch more after wake interval I believe...

Generally, you don't use encryption on sensor devices, even if they support it. It's more overhead and will drain the battery faster. Save encryption for Locks and similar devices.

I've always used encryption on all my Aeon MultiSensor 6 units. They are all hardwired in the ceiling. Maybe it's overkill, but they are part of my security concept that include triggering alarms, so I like the idea of using encryption on them. Anyway, regardless of that, something has clearly changed! Because what used to work, now does not! Including without encryption does work, so I'll probably just leave it at that unless someone has a pointed suggestion or solution. Cheers!

(@FlyingDiver: And separately, thank you for all of your awesome plugins over the years!!)