Very slow ttfb even when using default configuration of lscache plugin.

Hi,
I am using lite speed server with ls cache enable. When the cache is hit ttfb is good. But on the first try it is very very bad as compare to no cache plugin:
without lscache plugin: 800 ms
with ls cache plugin default setting: 4.2 seconds(almost tried 5-6 times)

How to resolve this?? i have not even started the optimization process still it shows very bad result consistently??
Running vultr high freq server.

Start by reproducing the reported first-request timing with the LiteSpeed Cache for WordPress plugin enabled using its default configuration, then compare it with the plugin-disabled case described in the issue. Record the server and WordPress conditions involved; done means identifying the cause of the 4.2-second delay or documenting the missing information needed to investigate it.

Written by the indexing model from the issue text.