Two requests, one is a feature request. The other will help the community.
Community Request: When updating the platform where it breaks some currently working features - such as the Xiaomi sensors, or where there is a significant likelihood of breaking something, can we please have some advance notice. There are already people wanting to roll back until some of these features are fixed.
Feature Request: When updating or creating a device driver, any coding errors cause the text of the device driver to be removed from the page, and an error pops us. Previously, the driver text remained on screen for editing, along with the errors. Makes it difficult to debug when this occurs.
You mean like this notice towards the beginning of the release notes for 2.0.5 that you surely read before applying the optional update whose installation you are in total control of to your hub?
(It was also mentioned well before release in the Xiaomi driver thread by author, who was contacted by Hubitat staff during beta testing of 2.0.5 after your friendly neighborhood tester[s] discovered the issue.) That being said, if you haven't applied two or more hotfixes in 2.0.5 yet, a 2.0.4 build should still be available in the port 8081 interface for you to roll back to if you want. See: Rollback to 2.0.4? (and if it's too late for you and the Xiaomi drivers don't get updated before then, Support can probably manually make an older version available to your hub if you ask nicely, or at least I think this is something they've been able to do in the past).
Just tried on both my hubs and the "old," expected behavior is still happening for me, so I wasn't able to reproduce this. Firefox 65 on macOS 10.14, for what it's worth.