Is there a way to find out if a block on my account was made in error, perhaps triggered by at least two bounties I created which possibly resulted in a rapid reduction in rep? (I have no idea why it may have triggered, but I am trying to understand what may have caused it).
Perhaps surprisingly, but reputation does not affect whether you're question banned or not. (Of course, gaining upvotes helps both in increasing your reputation and avoiding the ban, but there is no direct link.)
All information you need can be found in the FAQ on Meta Stack Exchange: What can I do when getting "We are no longer accepting questions/answers from this account"?
As Glorfindel mentioned, to my knowledge your rep probably doesn't influence the question ban. That said, you've had a bunch of questions which were downvoted and deleted which seemed to trigger the question ban and the ban seems to have been cleared for now