Adding 2 lines fixes these:
# diff -u /var/www/html/wordpress/wp-content/plugins/tinymce-advanced/tinymce-advanced.php.orig /var/www/html/wordpress/wp-content/plugins/tinymce-advanced/tinymce-advanced.php
--- /var/www/html/wordpress/wp-content/plugins/tinymce-advanced/tinymce-advanced.php.orig 2023-06-17 15:01:03.317114432 +0200
+++ /var/www/html/wordpress/wp-content/plugins/tinymce-advanced/tinymce-advanced.php 2023-06-17 14:59:51.814708294 +0200
@@ -57,6 +57,7 @@
private $toolbar_2;
private $toolbar_3;
private $toolbar_4;
+ private $toolbar_classic_block;
private $used_buttons = array();
private $all_buttons = array();
private $buttons_filter = array();
@@ -81,6 +82,7 @@
'toolbar_2' => 'fontselect,fontsizeselect,outdent,indent,pastetext,removeformat,charmap,wp_more,forecolor,table,wp_help',
'toolbar_3' => '',
'toolbar_4' => '',
+ 'toolbar_classic_block' => [],
'toolbar_classic_block' => 'formatselect,bold,italic,blockquote,bullist,numlist,alignleft,aligncenter,alignright,' .
'link,forecolor,backcolor,table,wp_help',