Reusable blocks appear to be entangled

I use a lot of blocks. Unfortunately, during a recent WordPress upgrade (not sure which one), my reusable blocks broke.

Most blocks just turned into regular paragraphs in my posts and are no longer recognized as reusable. I have tried converting a couple of these back into reusable blocks but weird stuff happened. Some blocks now seem to have become linked with each other. If I update one, it updates the other, even provides a warning about updating the other block.

I have deleted the affected blocks and recreated them (now 3769 and 3770 below), but to no avail. I have tried the suggested troubleshooting steps for this forum, also with no affect.

I’m at a loss and needing some guidance. Multiple blocks are used on every post so please be cautious of any suggestion that will require manually updating 200+ posts.

+------+------------------------+----------------------------+------------------------------------------------------------------------+-----------+-------------+
| ID   | post_title             | post_name                  | guid                                                                   | post_type | post_status |
+------+------------------------+----------------------------+------------------------------------------------------------------------+-----------+-------------+
|  605 | Disparity              | untitled-reusable-block    | https://www.worthwhilewatch.com/2020/06/02/untitled-reusable-block/    | wp_block  | publish     |
|  642 | Content Warning        | untitled-reusable-block-4  | https://www.worthwhilewatch.com/2020/06/03/untitled-reusable-block-4/  | wp_block  | publish     |
|  684 | Anthology Note         | untitled-reusable-block-5  | https://www.worthwhilewatch.com/2020/06/03/untitled-reusable-block-5/  | wp_block  | publish     |
|  838 | Waste of Time          | untitled-reusable-block-6  | https://www.worthwhilewatch.com/2020/06/05/untitled-reusable-block-6/  | wp_block  | publish     |
| 1062 | Disclaimer             | untitled-reusable-block-7  | https://www.worthwhilewatch.com/2020/06/24/untitled-reusable-block-7/  | wp_block  | publish     |
| 1185 | Why?                   | untitled-reusable-block-8  | https://www.worthwhilewatch.com/2020/08/07/untitled-reusable-block-8/  | wp_block  | publish     |
| 2220 | Tagline                | untitled-reusable-block-9  | https://www.worthwhilewatch.com/2020/08/13/untitled-reusable-block-9/  | wp_block  | publish     |
| 2881 | Must Read              | untitled-reusable-block-10 | https://www.worthwhilewatch.com/2020/09/03/untitled-reusable-block-10/ | wp_block  | publish     |
| 2882 | Worthwhile Read        | untitled-reusable-block-11 | https://www.worthwhilewatch.com/2020/09/03/untitled-reusable-block-11/ | wp_block  | publish     |
| 3769 | Must Watch Block       | must-watch-block           | https://www.worthwhilewatch.com/?p=3769                                | wp_block  | publish     |
| 3770 | Worthwhile Watch Block | worthwhile-watch-block     | https://www.worthwhilewatch.com/?p=3770                                | wp_block  | publish     |
+------+------------------------+----------------------------+------------------------------------------------------------------------+-----------+-------------+
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