WordPress database error Illegal mix of collations

Hello!

I found out my error_log is full on database errors related to Relevanssi like this one:

[06-Nov-2022 21:22:15 UTC] WordPress database error Illegal mix of collations (utf8_general_ci,IMPLICIT) and (utf8mb4_unicode_520_ci,COERCIBLE) for operation '=' for query SELECT DISTINCT(relevanssi.doc), relevanssi.*, relevanssi.title * 5 +
relevanssi.content * 1 + relevanssi.comment * 0.75 +
relevanssi.tag * 0.75 + relevanssi.link * 0 +
relevanssi.author + relevanssi.category * 0.75 + relevanssi.excerpt +
relevanssi.taxonomy + relevanssi.customfield + relevanssi.mysqlcolumn AS tf
FROM wp_relevanssi AS relevanssi WHERE relevanssi.term = '🚇ivermectin' ORDER BY tf DESC LIMIT 500 made by require('wp-blog-header.php'), wp, WP->main, WP->query_posts, WP_Query->query, WP_Query->get_posts, apply_filters_ref_array('posts_pre_query'), WP_Hook->apply_filters, relevanssi_query, relevanssi_do_query, relevanssi_search

Any ideas about why this is happening and how to fix it?

Thanks,
Ángel.-