[Bug]: Server lag issue

[Holy-Fak]

General Info

• [X] I didn't added any mods
• [ ] I can reproduce this issue consistently in single-player
• [X] I can reproduce this issue consistently in multi-player
• [X] I have searched for this issue previously and it was either (1) not previously reported, or (2) previously fixed and I am having the same problem.
• [ ] I am crashing and can provide my crash report(s)
• [X] I am using the latest version of the modpack

Your launcher

Curseforge

Modpack version

1.8

Describe your issue

Server tps is fine, but someone connet to server will lag like package lost, other modpack run on this server won't lag like that.

Compare others modpack, i noticed server upload data unusually high.

Steps to reproduce the issue

No response

Additional Information

.

[Holy-Fak]

java version: jdk 17.0.6+10

[DoctorMage]

server specs cpu total ram

[Holy-Fak]

server specs cpu total ram

cpu: i5-9600k ram: 32G i figure out probably is network issue.