Comment 27 for bug 1841826

Well, in the case of a Lenovo 4338, a quick google shows it is based on the SMSC2517, (https://joes-tech-blog.blogspot.com/2017/09/whats-inside-lenovo-docking-station-for.html) and well, another quick google show SMSC was aquired by Microchip, and after a third Google, I can tell you the USB controller chip and see that it even has published suspend-related errata that they do not plan on fixing that was discovered in Windows 8 days.

Some excerpts below:

Module 1:
End of User Impacts:
Port might fail to go into SUSPEND.

Solution:
This will not be addressed in a future version of the device.

Module 2:
End of User Impacts:
Device might not enumerate.

Solution:
Use external power on reset circuit (for example, reset circuit with MAX809S(V2.9V) voltage supervisor)

https://ww1.microchip.com/downloads/en/DeviceDoc/80000628A.pdf

Likely these quirks are not being backported into the drivers, to workaround in software for certain scenarios, and so are being stumbled upon with more advanced multi-device scenarios now supported in newer Ubuntu versions.

I would isolate the dock showing that the scenario works with a different port replicator/chip, and then either

a) use the other port replicator
b) reach out to the maintainer of the driver, see if you can give him some hardware, a reproducable scenario, you might be able to get a fix
c) find a developer for hire, do the same, upstream a patch