Database error

I am getting the following error generated in my php error log:

[05-Mar-2019 05:56:17 UTC] WordPress database error Illegal mix of collations (utf8mb4_unicode_ci,IMPLICIT) and (utf8mb4_unicode_520_ci,IMPLICIT) for operation ‘=’ for query SELECT tt.term_id, MAX(p.post_modified_gmt) AS date_gmt, l.country_slug AS country, l.region_slug AS region, l.city_slug AS city FROM rhp_31_geodir_post_locations l LEFT JOIN rhp_31_geodir_gd_place_detail pd ON ( pd.country = l.country AND pd.region = l.region AND pd.city = l.city ) LEFT JOIN rhp_31_posts p ON p.ID = pd.post_id LEFT JOIN

rhp_31_term_relationships

AS tr ON tr.object_id = p.ID LEFT JOIN

rhp_31_term_taxonomy

AS tt ON ( tt.term_taxonomy_id = tr.term_taxonomy_id AND tt.taxonomy = ‘gd_placecategory’ ) WHERE p.post_type = ‘gd_place’ AND p.post_status = ‘publish’ AND l.location_id IS NOT NULL AND tt.term_id IS NOT NULL GROUP BY CONCAT(tt.term_id, ‘-‘, l.country_slug, ‘-‘, l.region_slug, ‘-‘, l.city_slug) ORDER BY date_gmt DESC made by require(‘/wordpress-5.0.2/wp-blog-header.php’), wp, WP->main, WP->query_posts, WP_Query->query, WP_Query->get_posts, do_action_ref_array, WP_Hook->do_action, WP_Hook->apply_filters, WPSEO_Sitemaps->redirect, WPSEO_Sitemaps->build_sitemap, WPSEO_Sitemaps->build_root_map, WPSEO_Sitemaps_Renderer->get_index, apply_filters(‘wpseo_sitemap_index’), WP_Hook->apply_filters, GeoDir_Location_SEO::wpseo_sitemap_index, GeoDir_Location_SEO::wpseo_taxonomy_sitemap_index, GeoDir_Location_SEO::wpseo_sitemap_get_locations_taxonomies