[Waiting for user feedback] Performance slowdown after installing WPML

Background of the issue:
After we installed and activated WPML on our website, hidden link, we experienced a performance slowdown. We didn't have much issue in the development environment, but once we activated it on our production system, we have had persistent performance issues for many months already.

We have already followed your guides that have been provided to us：
https://wpml.org/faq/how-to-debug-performance-problems/
https://wpml.org/forums/topic/how-can-i-improve-performance-of-a-slow-site/
We can confirmed that we don't have the performance affecting features enabled on our production site. And have try most of the solution except for upgrading the php version. so far we haven't seen much improvement.

This is what we found to be one of the most repeating query by debug bar, but it does not seems to be especially anomalous: SELECT wpml_translations.translation_id, wpml_translations.element_id, wpml_translations.language_code, wpml_translations.source_language_code, wpml_translations.trid, wpml_translations.element_type FROM wp_icl_translations wpml_translations JOIN wp_term_taxonomy tax ON wpml_translations.element_id = tax.term_taxonomy_id AND wpml_translations.element_type = CONCAT('tax_', tax.taxonomy) JOIN wp_icl_translations tridt ON tridt.element_type = wpml_translations.element_type AND tridt.trid = wpml_translations.trid WHERE tridt.element_id IN(******)
where **** is various integer ids

Symptoms:
Performance slowdown after installing WPML, with higher CPU usage and database load, especially in the admin backend. he issue seems to manifest in generally much higher CPU usage on the WP server and also our database. The slowdown is most noticeable in the admin backend, since we have caching for most frontend stuff. Currently we are forced to upgrade our database and service instances to keep up, but this added a lot of cost to our server hosting.

Questions:
We want to know if there is any other things to check why wpml slow our server down so much and any solution to resolve the problem.