building client and server bps to address lag

we made a rough draft of our game and we are starting to get an actual grasp on how things work and how to do things in bp logic. Our main issue with our rough draft was that under any amount of lag the clients were unplayable even with a 10ms difference. the game runs fine on lan. listen server and dedicated did not make a difference. I made a child of our character class and messed with replication values. I was able to get the lag to happen a lil slower but that was all. I may need to add that player base walk speed is 1,000 replicated boost allows 10,000. flying no boost is 15,000 and boosted flying is 100,000. the main issue happens when just walking along the ground. there is a lil jitter in air under boost. like I said we are replicating things that are not already replicating. is this kind of lag on clients normal. id like to keep the game playable at 100 ping but even a small 50 ping the lag is still there. the only time clients are smoothe is on lan. we plan on rebuilding everything so im not scared of starting over. if anyone has any tips on how to handle server and clients. this is not a 3d asset heavy project. we have most of what we need visually. we just need to know how to handle lag. we are on version 4.22.3

I doubt the standard Character Movement Component is prepared to handle that kind of speed. You should instead make your own predictions and reconciliation of the movement based on what moves are possible or just scale down the speed and use other effects to make it appear to be really fast.

I ended finding the camera being replicated was causing the problem. the problem was occurring even at 2 mph. I couldn’t get it fixed until I detached some components from one another and stopped replicating some. not sure what exactly fixed it