Please get back to us with the result of the steps mentioned int he chat:
- IMPORTANT STEP! Create a backup of your website. Or better approach will be to test this on a copy/staging version of the website to avoid any disruption of a live website.
- Switch to the default theme such as "TwentyTwenty" by going to "WordPress Dashboard > Appearance > themes".
- Go to "WordPress Dashboard > Plugins" and deactivate all plugins except Woocommerce, WPML Multilingual CMS, WPML String Translation and Woocommerce Multilingual.
- Check if you can still recreate the issue.
- If not, re-activate your plugins one by one and check the issue each time to find out the plugin that causes the problem.
Also set the next reply as private by checking the checkbox below the reply box and provide the login information for the copied site so we can investigate more.
After duplicating my site, I began disabling plugins one by one to identify the cause of the excessive queries on taxonomy pages (such as categories, brands, attributes, etc.).
I eventually found the culprit: WPML SEO (version 2.2.2). Once I disabled it, the number of queries on category pages dropped from around 3,000 to just 500 (could be better, but I'll take it for now), and the page speed returned to normal.
I'm not exactly sure what WPML SEO does under the hood or why it was causing such a slowdown, but for now, I’ve had to keep it disabled. Hopefully, this issue will be resolved in a future update.
