Okay, a few things - First of all, if you have an issue with Rufus, you should try to use the
official issue tracker, as I only stumble onto these kind of forum posts when actively looking for them... which is rarely. Granted, the issue tracker may not be as convenient or familiar compared to using this forum, but, really, this (or direct e-mail) is the
only way you can be guaranteed to reach the author of the application and possibly get an answer to your problem.
Now, if you look at the issue tracker, you'll see that there already exists
an issue opened just for that problem, where I also reported that, while buid 10565 has some improvements, it does NOT consistently solve it. I'm hoping that, at some stage, Microsoft will finally get their act together and fix it one and for all, but it's up to them... Still, you can help pushing for this by making sure you report it (or upvote similar issues) in Feedback reports for "Hardware, Devices and Drivers" → "USB devices and connectivity".
Finally, you may want to try a new cheat mode that was introduced with Rufus 2.5 BETA (which you can download
here - be mindful that it's not available in Rufus 2.4 or earlier), that disables exclusive drive locking. If you run Rufus 2.5, and press
Alt-
, on your keyboard (that's the 'Alt' and comma keys), you will be able to toggle exclusive locking, which may help. However, I don't see it as a proper solution (the problem really is with Microsoft), which is why it's only a cheat mode.
Hope that helps.