I do not have any specific caching plugins except WP-Optomize. The only other plugin, I am aware of, that uses caching is Smart Slider. I cleared the caches in Smart Slider and WP-Optomize.
My site has slowed down after the last few WP upgrades. No idea why as I have not added / changed any pages or added any plugins. I did have a few large packet errors, this year, which I have not seen in the previous eight years of using WP.
“WordPress database error Got a packet bigger than ‘max_allowed_packet’ bytes for query UPDATE wpfh1_options
SET option_value
.”
These packet errors range in size from 2,101kb to 10,151kb in size.