Uncaught Exception: DateTime::__construct() in class-author.php:152

The following message sequence is appearing repeatedly on a multi-author blog using PHP 8.2:

[02-Jul-2023 05:24:10 UTC] PHP Fatal error:  Uncaught Exception: DateTime::__construct(): Failed to parse time string (1535096261) at position 7 (2): Unexpected character in [ROOT]/wp-content/plugins/seo-by-rank-math/includes/modules/sitemap/providers/class-author.php:152
Stack trace:
#0 [ROOT]/wp-content/plugins/seo-by-rank-math/includes/modules/sitemap/providers/class-author.php(152): DateTime->__construct()
#1 [ROOT]/wp-content/plugins/seo-by-rank-math/includes/modules/sitemap/providers/class-author.php(128): RankMath\Sitemap\Providers\Author->get_sitemap_url()
#2 [ROOT]/wp-content/plugins/seo-by-rank-math/includes/modules/sitemap/class-generator.php(169): RankMath\Sitemap\Providers\Author->get_sitemap_links()
#3 [ROOT]/wp-content/plugins/seo-by-rank-math/includes/modules/sitemap/class-generator.php(135): RankMath\Sitemap\Generator->build_sitemap()
#4 [ROOT]/wp-content/plugins/seo-by-rank-math/includes/modules/sitemap/class-sitemap-xml.php(166): RankMath\Sitemap\Generator->get_output()
#5 [ROOT]/wp-content/plugins/seo-by-rank-math/includes/modules/sitemap/class-sitemap-xml.php(153): RankMath\Sitemap\Sitemap_XML->build_sitemap()
#6 [ROOT]/wp-content/plugins/seo-by-rank-math/includes/modules/sitemap/class-sitemap-xml.php(92): RankMath\Sitemap\Sitemap_XML->has_sitemap_in_cache()
#7 [ROOT]/wp-content/plugins/seo-by-rank-math/includes/modules/sitemap/class-sitemap-xml.php(82): RankMath\Sitemap\Sitemap_XML->output()
#8 [ROOT]/wp-content/plugins/seo-by-rank-math/includes/modules/sitemap/class-router.php(79): RankMath\Sitemap\Sitemap_XML->__construct()
#9 [ROOT]/wp-includes/class-wp-hook.php(308): RankMath\Sitemap\Router->request_sitemap()
#10 [ROOT]/wp-includes/class-wp-hook.php(332): WP_Hook->apply_filters()
#11 [ROOT]/wp-includes/plugin.php(565): WP_Hook->do_action()
#12 [ROOT]/wp-includes/class-wp-query.php(1131): do_action_ref_array()
#13 [ROOT]/wp-includes/class-wp-query.php(1857): WP_Query->parse_query()
#14 [ROOT]/wp-includes/class-wp-query.php(3787): WP_Query->get_posts()
#15 [ROOT]/wp-includes/class-wp.php(663): WP_Query->query()
#16 [ROOT]/wp-includes/class-wp.php(783): WP->query_posts()
#17 [ROOT]/wp-includes/functions.php(1334): WP->main()
#18 [ROOT]/wp-blog-header.php(16): wp()
#19 [ROOT]/index.php(17): require('/home/perweb/pu...')
#20 {main}
  thrown in [ROOT]/wp-content/plugins/seo-by-rank-math/includes/modules/sitemap/providers/class-author.php on line 152

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