Fatal Error: glossary-shortcode.php on line 20

The glossary page was working fine on v5.4, but when it updated to v5.5 it broke the glossary page completely.

Fatal error: Uncaught TypeError: array_key_exists(): Argument #2 ($array) must be of type array, bool given in /[website]/wp-content/plugins/bluet-keywords-tooltip-generator/glossary-shortcode.php:20 Stack trace: #0 /[website]/wp-includes/shortcodes.php(434): tltpy_glossary(Array, '', 'tooltip_glossar...') #1 [internal function]: do_shortcode_tag(Array) #2 /[website]/wp-includes/shortcodes.php(273): preg_replace_callback('/\\[(\\[?)(toolti...', 'do_shortcode_ta...', '[tooltip_glossa...') #3 /[website]/wp-includes/class-wp-hook.php(324): do_shortcode('[tooltip_glossa...') #4 /[website]/wp-includes/plugin.php(205): WP_Hook->apply_filters('[tooltip_glossa...', Array) #5 /[website]/wp-includes/rest-api/endpoints/class-wp-rest-posts-controller.php(1933): apply_filters('the_content', '<!-- wp:shortco...') #6 /[website]/wp-includes/rest-api/endpoints/class-wp-rest-posts-controller.php(635): WP_REST_Posts_Controller->prepare_item_for_response(Object(WP_Post), Object(WP_REST_Request)) #7 /[website]/wp-includes/rest-api/class-wp-rest-server.php(1292): WP_REST_Posts_Controller->get_item(Object(WP_REST_Request)) #8 /[website]/wp-includes/rest-api/class-wp-rest-server.php(1125): WP_REST_Server->respond_to_request(Object(WP_REST_Request), '/wp/v2/pages/(?...', Array, NULL) #9 /[website]/wp-includes/rest-api.php(576): WP_REST_Server->dispatch(Object(WP_REST_Request)) #10 /[website]/wp-includes/rest-api.php(2957): rest_do_request(Object(WP_REST_Request)) #11 [internal function]: rest_preload_api_request(Array, '/wp/v2/pages/82...') #12 /[website]/wp-includes/block-editor.php(756): array_reduce(Array, 'rest_preload_ap...', Array) #13 /[website]/wp-admin/edit-form-blocks.php(77): block_editor_rest_api_preload(Array, Object(WP_Block_Editor_Context)) #14 /[website]/wp-admin/post.php(187): require('/Users/mattk/Lo...') #15 {main} thrown in /[website]/wp-content/plugins/bluet-keywords-tooltip-generator/glossary-shortcode.php on line 20

I tried the solution in this post, but it didn’t work for me.

For now, I just took the glossary-shortcode.php code from v5.4 and pasted it over the v5.5 code and it’s working again, but I’m hoping for a less hacky solution.

I’m not sure what other info you need, so:
WordPress: 6.7.1
PHP: 8.2.27
Multisite: No