Modbus RTU over TCP connection problem


We have high load project on windows server. Ignition version 7.5.12. System says thad java open ~525 threads. There more 80 OPC devices on the project. We add 2 new MRTUoTCP devices, and add tags on the project. There is remote devices with not so stable connection. Some times we see that ignition report that connection status on that devises is “Connected”

but gateway shows that have no connection

all tags on “bad quality state”. Ignition reconnect sometimer only if I reanable this devices, or restart ignition service. Work correctly some time, with reconnections, readind tags, timeouts, all is good. but in few days we have this problem again. “Reconnect After Consecutive Timeouts” enabled.
Can you, please, help with this issue?