Sudden “Missed Schedule” error only with revisions

Had several revisions, on two separate WP sites (one is a multisite), scheduled to post at a few different days/times over the holiday weekend and they all failed to post with a “missed schedule” error. And still getting the error today if I try to schedule any revisions.

New posts that were scheduled posted with no error, so this seems to be a problem only with revisions, using this plugin.

This is what our error log says:

[01-Dec-2019 16:00:42 UTC] PHP Fatal error:  Uncaught Error: Call to a member function isBlockEditorActive() on null in /home4/redacted/public_html/redacted/wp-content/plugins/revisionary/revision-creation_rvy.php:340
Stack trace:
#0 /home4/redacted/public_html/redacted/wp-content/plugins/revisionary/revisionary_main.php(687): PublishPress\Revisions\RevisionCreation->flt_create_scheduled_rev(Array, Array)
#1 /home4/redacted/public_html/redacted/wp-includes/class-wp-hook.php(288): Revisionary->flt_create_scheduled_rev(Array, Array)
#2 /home4/redacted/public_html/redacted/wp-includes/plugin.php(206): WP_Hook->apply_filters(Array, Array)
#3 /home4/redacted/public_html/redacted/wp-includes/post.php(3881): apply_filters('wp_insert_post_...', Array, Array)
#4 /home4/redacted/public_html/redacted/wp-includes/post.php(4196): wp_insert_post(Array, false)
#5 /home4/redacted/public_html/redacted/wp-content/plugins/revisionary/admin/revision-action_rvy.php(411): wp_update_post(Array)
#6 /home4/redacted/public_html/redacted/wp-content/plugins/revisionary/admin/revis in /home4/redacted/public_html/redacted/wp-content/plugins/revisionary/revision-creation_rvy.php on line 340