PHP errors

We are getting quite often errors in our PHP log:

WordPress database error Illegal mix of collations (utf8_general_ci,IMPLICIT) and (utf8mb4_unicode_ci,COERCIBLE) for operation ‘=’ for query SELECT histid FROM vfgru_aryo_activity_log
WHERE user_caps = ‘administrator’
AND action = ‘created’
AND object_type = ‘Taxonomy’
AND object_subtype = ‘yst_prominent_words’
AND object_name = ‘game 🙂’
AND user_id = ‘1’
AND hist_ip = ‘37.48.49.101’
AND hist_time = ‘1562331218’
; made by require(‘wp-blog-header.php’), wp, WP->main, WP->parse_request, do_action_ref_array(‘parse_request’), WP_Hook->do_action, WP_Hook->apply_filters, rest_api_loaded, WP_REST_Server->serve_request, WP_REST_Server->dispatch, WP_REST_Terms_Controller->create_item, wp_insert_term, do_action(‘created_term’), WP_Hook->do_action, WP_Hook->apply_filters, AAL_Hook_Taxonomy->hooks_created_edited_deleted_term, aal_insert_log, AAL_API->insert

or

WordPress database error Illegal mix of collations (utf8_general_ci,IMPLICIT) and (utf8mb4_unicode_ci,COERCIBLE) for operation ‘=’ for query SELECT histid FROM vfgru_aryo_activity_log
WHERE user_caps = ‘administrator’
AND action = ‘created’
AND object_type = ‘Taxonomy’
AND object_subtype = ‘yst_prominent_words’
AND object_name = ‘a.m 🙂’
AND user_id = ‘1’
AND hist_ip = ‘37.48.49.101’
AND hist_time = ‘1562328987’
; made by require(‘wp-blog-header.php’), wp, WP->main, WP->parse_request, do_action_ref_array(‘parse_request’), WP_Hook->do_action, WP_Hook->apply_filters, rest_api_loaded, WP_REST_Server->serve_request, WP_REST_Server->dispatch, WP_REST_Terms_Controller->create_item, wp_insert_term, do_action(‘created_term’), WP_Hook->do_action, WP_Hook->apply_filters, AAL_Hook_Taxonomy->hooks_created_edited_deleted_term, aal_insert_log, AAL_API->insert

or

WordPress database error Column ‘object_subtype’ cannot be null for query INSERT INTO vfgru_aryo_activity_log (action, object_type, object_subtype, object_name, object_id, user_id, user_caps, hist_ip, hist_time) VALUES (‘updated’, ‘Post’, NULL, ‘(no title)’, NULL, 3132, ‘editor’, ‘2604:2d80:e514:2f00:a580:766b:2556:b55a’, 1562289258)made by do_action(‘wp_ajax_nelio_content_add_post_reference’), WP_Hook->do_action, WP_Hook->apply_filters, Nelio_Content_Reference_Ajax_API->add_post_reference, Nelio_Content_Reference->autoload, Nelio_Content_Reference->set_title, Nelio_Content_Reference->maybe_update_status, wp_update_post, wp_insert_post, wp_transition_post_status, do_action(‘transition_post_status’), WP_Hook->do_action, WP_Hook->apply_filters, AAL_Hook_Posts->hooks_transition_post_status, aal_insert_log, AAL_API->insert

Can you check it please?

Thank you.