Disabling XML-RPC results in fatal error

I toggled disable XML-RPC and now I’m getting a fatal error. I can’t load the settings page at all to disable the toggle. Here is my debug.log:

[11-Apr-2024 11:16:31 UTC] PHP Fatal error:  Uncaught TypeError: call_user_func_array(): Argument #1 ($callback) must be a valid callback, function "_return_false" not found or invalid function name in /nas/content/live/ingeniumtc2023/wp-includes/class-wp-hook.php:324
Stack trace:
#0 /nas/content/live/ingeniumtc2023/wp-includes/plugin.php(205): WP_Hook->apply_filters(true, Array)
#1 /nas/content/live/ingeniumtc2023/wp-content/plugins/really-simple-ssl/security/tests.php(149): apply_filters('xmlrpc_enabled', true)
#2 /nas/content/live/ingeniumtc2023/wp-content/plugins/really-simple-ssl/security/sync-settings.php(79): rsssl_xmlrpc_enabled()
#3 /nas/content/live/ingeniumtc2023/wp-includes/class-wp-hook.php(324): rsssl_disable_fields(Array, 'disable_xmlrpc')
#4 /nas/content/live/ingeniumtc2023/wp-includes/plugin.php(205): WP_Hook->apply_filters(Array, Array)
#5 /nas/content/live/ingeniumtc2023/wp-content/plugins/really-simple-ssl/settings/config/config.php(1754): apply_filters('rsssl_field', Array, 'disable_xmlrpc')
#6 /nas/content/live/ingeniumtc2023/wp-content/plugins/really-simple-ssl/settings/settings.php(769): rsssl_fields()
#7 /nas/content/live/ingeniumtc2023/wp-includes/rest-api/class-wp-rest-server.php(1193): rsssl_rest_api_fields_get(Object(WP_REST_Request))
#8 /nas/content/live/ingeniumtc2023/wp-includes/rest-api/class-wp-rest-server.php(1041): WP_REST_Server->respond_to_request(Object(WP_REST_Request), '/reallysimpless...', Array, NULL)
#9 /nas/content/live/ingeniumtc2023/wp-includes/rest-api/class-wp-rest-server.php(431): WP_REST_Server->dispatch(Object(WP_REST_Request))
#10 /nas/content/live/ingeniumtc2023/wp-includes/rest-api.php(424): WP_REST_Server->serve_request('/reallysimpless...')
#11 /nas/content/live/ingeniumtc2023/wp-includes/class-wp-hook.php(324): rest_api_loaded(Object(WP))
#12 /nas/content/live/ingeniumtc2023/wp-includes/class-wp-hook.php(348): WP_Hook->apply_filters('', Array)
#13 /nas/content/live/ingeniumtc2023/wp-includes/plugin.php(565): WP_Hook->do_action(Array)
#14 /nas/content/live/ingeniumtc2023/wp-includes/class-wp.php(418): do_action_ref_array('parse_request', Array)
#15 /nas/content/live/ingeniumtc2023/wp-includes/class-wp.php(813): WP->parse_request('')
#16 /nas/content/live/ingeniumtc2023/wp-includes/functions.php(1336): WP->main('')
#17 /nas/content/live/ingeniumtc2023/wp-blog-header.php(16): wp()
#18 /nas/content/live/ingeniumtc2023/index.php(17): require('/nas/content/li...')
#19 {main}
  thrown in /nas/content/live/ingeniumtc2023/wp-includes/class-wp-hook.php on line 324
[11-Apr-2024 11:16:33 UTC] PHP Fatal error:  Uncaught TypeError: call_user_func_array(): Argument #1 ($callback) must be a valid callback, function "_return_false" not found or invalid function name in /nas/content/live/ingeniumtc2023/wp-includes/class-wp-hook.php:324
Stack trace:
#0 /nas/content/live/ingeniumtc2023/wp-includes/plugin.php(205): WP_Hook->apply_filters(true, Array)
#1 /nas/content/live/ingeniumtc2023/wp-content/plugins/really-simple-ssl/security/tests.php(149): apply_filters('xmlrpc_enabled', true)
#2 /nas/content/live/ingeniumtc2023/wp-content/plugins/really-simple-ssl/security/sync-settings.php(79): rsssl_xmlrpc_enabled()
#3 /nas/content/live/ingeniumtc2023/wp-includes/class-wp-hook.php(324): rsssl_disable_fields(Array, 'disable_xmlrpc')
#4 /nas/content/live/ingeniumtc2023/wp-includes/plugin.php(205): WP_Hook->apply_filters(Array, Array)
#5 /nas/content/live/ingeniumtc2023/wp-content/plugins/really-simple-ssl/settings/config/config.php(1754): apply_filters('rsssl_field', Array, 'disable_xmlrpc')
#6 /nas/content/live/ingeniumtc2023/wp-content/plugins/really-simple-ssl/settings/settings.php(769): rsssl_fields()
#7 /nas/content/live/ingeniumtc2023/wp-content/plugins/really-simple-ssl/settings/settings.php(237): rsssl_rest_api_fields_get()
#8 /nas/content/live/ingeniumtc2023/wp-includes/class-wp-hook.php(324): rsssl_rest_api_fallback('')
#9 /nas/content/live/ingeniumtc2023/wp-includes/class-wp-hook.php(348): WP_Hook->apply_filters('', Array)
#10 /nas/content/live/ingeniumtc2023/wp-includes/plugin.php(517): WP_Hook->do_action(Array)
#11 /nas/content/live/ingeniumtc2023/wp-admin/admin-ajax.php(188): do_action('wp_ajax_rsssl_r...')
#12 {main}
  thrown in /nas/content/live/ingeniumtc2023/wp-includes/class-wp-hook.php on line 324