Looking at the patch, it says the real fix is the sleep for 1 second, correct? I did verify that setting DTS = True is redundant as you said, it's included in pyserial as a default state. I don't see anything wrong with the patch in general, but do have one question for the more senior devs here:

A question for the larger group here, I wonder if we could/should just push that line of code, time.sleep(1), up to the higher level serial class so that all drivers could take advantage of it? Specifically, do_upload() and do_download() in ./chirp/ui/mainapp.py

From: chirp_devel-bounces@intrepid.danplanet.com <chirp_devel-bounces@intrepid.danplanet.com> on behalf of interfect--- via chirp_devel <chirp_devel@intrepid.danplanet.com>
Sent: Saturday, September 5, 2020 11:45 PM
To: chirp_devel@intrepid.danplanet.com <chirp_devel@intrepid.danplanet.com>
Subject: [chirp_devel] Patch for UV5R driver to fix communication on Ubuntu 16.04 with pl2303-based cables (fixes #4165)

Hello,

Bernhard Hailer has asked me to resubmit my patch for the issue with modern Ubuntu serial drivers
having DTR low, at least when the port isn't open, causing the radio to be in transmit mode and not
ready to accept CHIRP's commands as soon as the port is open. This fixes #4165.

Issue: https://chirp.danplanet.com/issues/4165
Original patch submission (did anybody get it?):
http://intrepid.danplanet.com/pipermail/chirp_devel/2016-October/004329.html

I tried to send this message earlier after subscribing to the list and clicking the confirmation link in the subscription e-mail, but I think web based confirmation is broken. When I sent the patch I got a message saying it was held for moderation because I wasn't a member of the list. I had to subscribe again and confirm by e-mail instead to actually get onto the list.

Thanks,
-Adam