Why is google spamming my Wordpress site with dating keywords?

I have a Wordpress site getting hit with over 100k requests per day with the same request below. All these GETs are coming from about 200 different IPs within the same Google netrange (66.249.x.x). There is no /search/ route on the site, but something in Wordpress (Relevanssi?) must be processing this request because there are UTF-8 collation errors in the DB, probably due to the emojis or cyrillic characters:

WordPress database error Illegal mix of collations (utf8_general_ci,IMPLICIT) and (utf8mb4_unicode_ci,COERCIBLE) for operation 'like' for query \n\t\t\tSELECT COUNT(DISTINCT(relevanssi.doc))\n\t\t\t\tFROM 49qi0c_relevanssi AS relevanssi\n\t\t\t\t WHERE (relevanssi.term LIKE 'berbat\xf0\x9f\xaa\x80\xe2\x9d\xa4\xef\xb8\x8f\xef\xb8\x8fwww%' OR relevanssi.term_reverse LIKE CONCAT(REVERSE('berbat\xf0\x9f\xaa\x80\xe2\x9d\xa4\xef\xb8\x8f\xef\xb8\x8fwww'), '%')) 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, relevanssi_search, relevanssi_generate_df_counts, QM_DB->query

I checked the Relevanssi forum and found someone posting almost the same issue. It was said to be 'harmless' and didn't appear to concern anyone so the thread was closed. Thing is though, the sheer load of these requests are starting to lag the site and the errors being generated are filling up the logs under the /var/ partition. I've got the /19 from Google blocked right now but probably not the right answer since it's Google (page ranking and all that). Anyone ever see this kind of stuff from Google before?

GET /search/%F0%9F%AA%80BEST+DATING+SITE%E2%9D%A4%EF%B8%8F%EF%B8%8F%C4%B0ngiliz+kad%C4%B1n+i%C3%A7+%C3%A7ama%C5%9F%C4%B1r%C4%B1+gal+r%C3%B6ntgenci+%C3%B6n%C3%BCnde+berbat%F0%9F%AA%80%E2%9D%A4%EF%B8%8F%EF%B8%8FWww.MtSp.XyZ%F0%9F%AA%80%E2%9D%A4%EF%B8%8F%EF%B8%8F%C4%B0ngiliz+kad%C4%B1n+i%C3%A7+%C3%A7ama%C5%9F%C4%B1r%C4%B1+gal+r%C3%B6ntgenci+%C3%B6n%C3%BCnde+berbat+%C4%B0ngiliz+kad%C4%B1n+i%C3%A7+%C3%A7ama%C5%9F%C4%B1r%C4%B1+gal+r%C3%B6ntgenci+%C3%B6n%C3%BCnde+berbat+%C4%B0ngiliz+kad%C4%B1n+i%C3%A7+%C3%A7ama%C5%9F%C4%B1r%C4%B1+gal+r%C3%B6ntgenci+%C3%B6n%C3%BCnde+berbat/feed/rss2/?page_number_9=1&page_number_15=7&page_number_14=3&page_number_16=3&page_number_10=1&page_number_12=33&page_number_17=3&page_number_13=3&page_number_11=17 HTTP/1.1" 200 718084 "-" "Mozilla/5.0 (Linux; Android 6.0.1; Nexus 5X Build/MMB29P) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/97.0.4692.71 Mobile Safari/537.36 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)

I had blocked them in robot.txt

Disallow: /*?s=*

I had a lot of request similar to the following from googlebot

https://example.com/es/?s=%20Levitra%2010mg%20filmtabletten%20rezeptfrei%20Viagra%20original%20bei%20pfizer%20100mg%20kaufen%20in%20deutschland%F0%9F%92%88%E2%9C%97%20www.MayoClinic.store%20%E2%9C%97%F0%9F%92%88%20Rezeptfrei%20viagra%20oder%20%C3%A4hnliche%20mittel%20Kamagra%20in%20pattaya%20kaufen%20Kamagra%20deutschland%20100mg%20online%20kaufen%20kaufen%20Cialis%20sicher%20kaufen%20forum

Now they are gone the last one was on DIC 3 2022

These spam requests had two downsides for me:

1. These spam requests were wasting my crawling budget.

2. As I am an Ezoic partner, they have an app to control published content. The app is called Objectionable Content There you can see a list of pages that may have objectionable content on them.

In my case I had a long list of 404 error pages from these spam requests. And now they are gone, my site is clean.