Hello,
I have managed to reproduce issues #1 (quick connect button not working) and #3 (only system app selection for blacklist). Frustratingly, I can't right now reproduce #2 (VPN does not detect loss of connectivity), even though it's possibly the most important one, and it did happen again in the meantime while I wasn't collecting logs. I also can't reproduce #4 as I can now share Eddie's log - at least that's useful! I'm attaching both the Eddie log and the logcat - the period of interest is after 17:32 UTC (in the Eddie log) and 18:32 localtime (in the logcat). The only actions I performed were trying the quick start button, which failed to connect, and then displaying the blacklist app selection list. Please let me know whether this is helpful, and if there is anything else I can provide.
As the logs do contain some personally identifying information, I am emailing them separately to support.
P.S.: I think it's unlikely this is relevant, but for full disclosure the phone has, since my original report, been updated to the 1 September 2021 security update.