Problem With Cache. Slow Down The Website


I have problem with cs-cart speed..

after many hours.. or 1 day something happening with cache and it slow down the website..

if I go and clean the cache then the speed is ok..

is there any way to find out what happening?

CS-Cart Version: 4.2.4

PHP: 5.6.32

I also have set redis for "cache_backend.

Thank you