is there a reason that trains stop and go when the throttle is open if so maybe should look into trying to solve this issue

this screenshot is a example i will be going under 5mph and the engine stops but still shows the speed and wheels moving and its on the latest test build

same vid just diff channel name
https://www.youtube.com/watch?v=t6JaHstntL8

when i type /forge tps its at 20 and i can record again with F3 later

Are you single or multiplayer?

What do you get when you run /forge tps?

Would you mind recording the same video with F3 turned on?

new vid as requested showing the F3 menu as well as the server tps
https://youtu.be/oDr3CljnXzE

Ah you are on a server. If you hit tab you can see the ping delay. It's likely the ping delay causing the jerkiness

is there a way to stop ping delay or is that a client only issue?
im on the server rn and it did start at 2 bars in the tab but now its up to 5.
update im at 4 bars when i look at the tab so ping isnt as low
last update i looked when it happened i had 5/5 bars in the tab list so idk if that means ping delay or something different

Let me know if this is better in the new test builds. I reduced the amount of network data sent by IR each tick

all right i'll look next time the server runs on a test build but this is a issue that imo its not #1 on the list but eventually needs to be resolved