Duo keeps getting kicked at random intervals and sometimes lags through Steam server hosting by me. How to fix please?

[SleepyTraveler]

My friend and I can't figure it out. We both have decent PC setups and internet is fine. Games like Palworld, Peak, Deeprock Galactic, L4D2 and etc. that we played at did not have such issues. For Terraria, a pixel game, is a first time where my friend gets kicked randomly out of my server that I am hosting and even lags at times. We tried lowering his graphics and I observed it still happens even when nearby mobs are few. This was already an issue since the start of the game all the way till post-Mech.

Hoping for anyone's advice on this matter, thank you!