Stratum issue - Connection closed after invalid shares

[M1neK1ng]

Describe the bug
[2023-06-06 20:35:22.4016] [I] [coin] [0HMR5EARQGK22] Share rejected: duplicate share [xxxxxxxxx;bosminerxxxxxxxxx]
[2023-06-06 20:35:22.4619] [I] [coin] [0HMR5EARQGK22] Connection closed

Whenever the asic miner(s) (sha256) recieve an invalid share, the stratum closes the connection and often the stratum shows up as DEAD on the asic dashboard.

Its been going on since install and Ive tried tweaking the difficulty to minimize the invalid shares but cant resolve the problem since invalid shares are just a normal part of mining.

The server is a quad cpu, 64 bit, 16 gigs or ram, 500gb ssd hd and on 10gbit connection running ubuntu, ufw, fail2ban.

the connection is very quite. no traffic yet or attacks etc.

Is there something i can tweak or changed/modify to stop the stratum from dropping the connections and shaowing as dead?

Thanks