Accounting drop when authentication

[Ibrahemoo Ghost]

I use FreeRADIUS Version 3.0.20 as both proxy and (auth/acct) server.
I have more than 200 realms. Every one of them is redirecting to a
different site file with a separate sql module but with a shared sql_pool.

I recently had a strange problem, every time the system hits 150 auth
requests per second accounting packets drop from 1000 req/s to about 200
req/s and the system begins to delay accounting requests and accounting no
response log messages arise in connected clients.

The system operates normally under heavy load and no stress is visible to
me in the sql server. I am using a monitor system and it shows no drop or
increase in sql load.

During accounting drop the ssd usage drops from 80% to 20%.

My radiusd thread pool configuration for 36 cores and 256GB ram and
enterprise ssd is:
thread pool {
start_servers = 60
max_servers = 144
min_spare_servers = 20
max_spare_servers = 60
max_requests_per_server = 0
auto_limit_acct = no
}

My shared sql_pool around all 200 sql modules is:
pool {
start = 36
min = 18
max = 72
spare = 36
uses = 0
retry_delay = 30
 lifetime = 0
 idle_timeout = 60
}

I have already checked and tuned mysql server to best values and checked
the indices for the tables and everything is pretty well configured I am
80% sure the problem is with freeradius configuration because what solve
the problem temporarily is restarting freeradius service until it
rehits 150 auth req/s and problem rearise.

Do you agree with me that the problem is from freeradius or it could be
something else and what can I do to solve it ?

Thanks in advance

Ibrahem