[CQ-Contest] Broken Kenwood SiLabs USB driver

[Steve London]

I was helping someone debug a recent problem with invisible virtual serial
ports on a TS-890S. After a lot of head scratching, found this on

https://www.kenwood.com/i/products/info/amateur/vcp_e.html

Caution!
Please do not use the virtual COM port driver v11.4.0 released by Silicon
Laboratories on July 29, 2024. A problem has been confirmed where the
corresponding COM port becomes invisible in our PC applications. This
problem does not occur with v11.3.0, which can be downloaded from the link
above. If you encounter this problem with v11.4.0 downloaded from the
Silicon Laboratories website, you can avoid it by reverting to v11.3.0. (As
of August 1, 2024)

This also affects the TS-590.

73,
Steve, N2IC