Slow loading Category Page Magento 2.4.0

I am experiencing slow loading Category Pages using Magento 2.4.0. We have 27,000 products of which approximately 6,000 are for the Magento website. The other 21,000+ are for eBay and Amazon. Normal load time for a Category page with 5,000+ products is less than 2 seconds. Long load time for the same page can be 10+ seconds. I have found that I can make the Category Page load normally again if I reindex these six indexes and then clearing any Invalidated Cache files (usually Page Cache will be invalidated after a reindex).

  1. Category Products
  2. Product Categories
  3. Catalog Rule Product
  4. Product EAV
  5. Catalog Product Rule
  6. Product Price

I must check our website for slow loading Category Pages every couple of hours. I must reindex those 6 Product Indexes 3 or 4 times every day. I have not been able to find an error in the logs when this happens. And I have not been able to identify the cause. Any ideas will be greatly appreciated.
The website is hillcountrycustomcycles.com. We push a lot of graphics so the first page will take a couple of seconds to load. But after the initial load, the site should load quickly.