RankMath sitemap function throws an error and does not work

Hi,

RankMath sitemap function throws an error and does not work (I use FS_METHOD “direct” – so FTP is not in use).

So it wrongly initates FTP to write the sitemap.
File right are available.

BR

Christian

[09-Jan-2025 14:23:37 UTC] PHP Deprecated: Increment on non-alphanumeric string is deprecated in /var/www/houseaffair/wp-content/plugins/seo-by-rank-math/includes/modules/sitemap/providers/class-author.php on l ine 103
[09-Jan-2025 14:23:37 UTC] PHP Fatal error: Uncaught TypeError: ftp_fput(): Argument #1 ($ftp) must be of type FTP\Connection, null given in /var/www/houseaffair/wp-admin/includes/class-wp-filesystem-ftpext.php :212
Stack trace:
#0 /var/www/houseaffair/wp-admin/includes/class-wp-filesystem-ftpext.php(212): ftp_fput()
#1 /var/www/houseaffair/wp-content/plugins/seo-by-rank-math/includes/modules/sitemap/class-cache.php(135): WP_Filesystem_FTPext->put_contents()
#2 /var/www/houseaffair/wp-content/plugins/seo-by-rank-math/includes/modules/sitemap/class-sitemap-xml.php(155): RankMath\Sitemap\Cache->store_sitemap()
#3 /var/www/houseaffair/wp-content/plugins/seo-by-rank-math/includes/modules/sitemap/class-sitemap-xml.php(92): RankMath\Sitemap\Sitemap_XML->has_sitemap_in_cache()
#4 /var/www/houseaffair/wp-content/plugins/seo-by-rank-math/includes/modules/sitemap/class-sitemap-xml.php(82): RankMath\Sitemap\Sitemap_XML->output()
#5 /var/www/houseaffair/wp-content/plugins/seo-by-rank-math/includes/modules/sitemap/class-router.php(79): RankMath\Sitemap\Sitemap_XML->__construct()
#6 /var/www/houseaffair/wp-includes/class-wp-hook.php(324): RankMath\Sitemap\Router->request_sitemap()
#7 /var/www/houseaffair/wp-includes/class-wp-hook.php(348): WP_Hook->apply_filters()
#8 /var/www/houseaffair/wp-includes/plugin.php(565): WP_Hook->do_action()
#9 /var/www/houseaffair/wp-includes/class-wp-query.php(1140): do_action_ref_array()
#10 /var/www/houseaffair/wp-includes/class-wp-query.php(1868): WP_Query->parse_query()
#11 /var/www/houseaffair/wp-includes/class-wp-query.php(3852): WP_Query->get_posts()
#12 /var/www/houseaffair/wp-includes/class-wp.php(696): WP_Query->query()
#13 /var/www/houseaffair/wp-includes/class-wp.php(816): WP->query_posts()
#14 /var/www/houseaffair/wp-includes/functions.php(1336): WP->main()
#15 /var/www/houseaffair/wp-blog-header.php(16): wp()
#16 /var/www/houseaffair/index.php(17): require(‘…’)
#17 {main}
thrown in /var/www/houseaffair/wp-admin/includes/class-wp-filesystem-ftpext.php on line 212