More info here
https://github.com/johndoh/roundcube-sauserprefs/issues/72
https://github.com/johndoh/roundcube-sauserprefs/issues/73

diff -ruN sauserprefs-original/config.inc.php sauserprefs/config.inc.php
--- sauserprefs-original/config.inc.php	2022-10-28 18:21:08.067404158 +0200
+++ sauserprefs/config.inc.php	2022-10-28 18:16:49.105235594 +0200
@@ -73,7 +73,7 @@
 // Some configs have been renamed in SAv4, old config names are depreciated
 // see https://bz.apache.org/SpamAssassin/show_bug.cgi?id=7826 for more info
 // setting this config to true will make this plugin use the new config names
-$config['sauserprefs_sav4'] = false;
+$config['sauserprefs_sav4'] = true;
 
 // default settings
 // these are overridden by $GLOBAL and user settings from the database
diff -ruN sauserprefs-original/sauserprefs.js sauserprefs/sauserprefs.js
--- sauserprefs-original/sauserprefs.js	2022-06-18 09:15:24.000000000 +0200
+++ sauserprefs/sauserprefs.js	2022-10-28 18:11:17.221297366 +0200
@@ -359,8 +359,8 @@
                     $(obj).parents('thead').first().find('th').removeClass(rcmail.env.sauserprefs_table_sort_asc).removeClass(rcmail.env.sauserprefs_table_sort_desc);
                     $(obj).parent('th').addClass(asc ? rcmail.env.sauserprefs_table_sort_asc : rcmail.env.sauserprefs_table_sort_desc);
 
-                    rcmail.env.sauserprefs_sort[id] = [idx, asc];
-                    rcmail.save_pref({name: 'sauserprefs_sort', value: rcmail.env.sauserprefs_sort, env: true});
+                    rcmail.env.sauserprefs_sort[id] = [idx, asc.toString()];
+                    rcmail.save_pref({name: 'sauserprefs_sort', value: JSON.stringify(rcmail.env.sauserprefs_sort), env: true});
 
                     return false;
                 }, true);
@@ -379,4 +379,4 @@
             }
         }
     }
-});
\ No newline at end of file
+});
diff -ruN sauserprefs-original/sauserprefs.php sauserprefs/sauserprefs.php
--- sauserprefs-original/sauserprefs.php	2022-06-18 09:15:24.000000000 +0200
+++ sauserprefs/sauserprefs.php	2022-10-28 18:20:08.757594797 +0200
@@ -86,6 +86,9 @@
         $this->load_config();
         $this->_load_host_config();
 
+        // set SpamAssassin v4 mode (added v1.20)
+        self::$SAv4 = $this->rcube->config->get('sauserprefs_sav4', false);
+
         // Host exceptions
         $hosts = $this->rcube->config->get('sauserprefs_allowed_hosts');
         if (!empty($hosts) && !in_array($_SESSION['storage_host'], (array) $hosts)) {
@@ -257,7 +260,8 @@
             'sauserprefs.selectimportsource', 'import');
 
         // output table sorting prefs
-        $sorts = $this->rcube->config->get('sauserprefs_sort', []);
+        $sorts = $this->rcube->config->get('sauserprefs_sort');
+        $sorts = json_decode($sorts, true);
         if (!isset($sorts['#spam-langs-table'])) {
             $sorts['#spam-langs-table'] = [0, 'true'];
         }
@@ -1460,8 +1464,5 @@
 
         $file = $configs[$_SESSION['storage_host']];
         $this->load_config($file);
-
-        // set SpamAssassin v4 mode (added v1.20)
-        self::$SAv4 = $this->rcube->config->get('sauserprefs_sav4', false);
     }
 }