Describe the Bug

Im on a server in the ATM9 modpack with a relatively large rail system and if im sitting in a chair while the train is moving the train just stops atseemingly random intervals

Reproduction Steps

1. build a rail system 2k blocks in length
   2.sit in a chair
   3.ride train
   ...

Expected Result

Smooth train riding experience

Screenshots and Videos

Crash Report or Log

No response

Operating System

Win 10

Mod Version

0.5.1f

Minecraft Version

1.20.1

Forge Version

47.2.18

Other Mods

ATM9 modlist is 430+ mods in total

Additional Context

No response

After a bit more testing, it does not seem to be neither Modern Fix nor Very Many Players, which are mods that affect performance related stuff, and my biggest suspicion.

If I drive my train at 8 speed, it seems more stable too, so obviously has to do with the server being unable to keep up when driving faster. We don't really have much world gen going on though, and the strecthes I have been testing only had the train tracks beyond mostly vanilla worldgen, nothing else. Well, and then the train of course.

Even with the server hang-ups though, as I said, this did not used to happen in the older versions of Create/our modpack. The train might "hang", but it wouldn't kick you off the drivers' seat, getting you crushed by your own train when it "reloads". Anyway, some more insight into all this would be very nice, and a solution even better.

Could be because of some other things that have started happening on the server. We noticed recently that we had many gigs worth of log files that were clogging up our server backups, maybe the logging of all this debug info is causing problems to the server? - I just haven't found out where I can turn this off, cause the debug logs are not helping and just a waste of space/system resources right now.

I just updated my public modpack recently, and now the private server we are hosting is also running into this issue. I am driving my train across the world, and the train will just suddenly stop in place while at full speed, then resume up to several seconds later, or lose all momentum and grind to a halt.

The modpack I am maintaining is specifically designed to be "persistent", so mainly just mod updates, rather than mod additions. My current guess, is that something I updated is now causing problems for the Create trains.

Fortunately, I try to keep a changelog where I note down any mods that get updated, but the list got pretty long as I had been away from Minecraft for a while, and was just maintaining the modpack without playing.

So something must have changed "somewhere" since November last year.

I also run into another issue where the train I am riding just straight up unloads, kicking me out of it, which also never happened before. Not sure if related to this issue as well, but since both issues appeard simultaneous, I suspect it might be the case. Sometimes the train just unloads while standing still even.

I don't see anything in the log files either, other than "server can't keep up", both on client and on server, so that isn't really helpful either.

Would like to help figure out what is causing this problem, but after wasting several hours on trying to resolve/debug, I am at a loss. Other than rolling back the server to before the update I made, and then gradually update mods until it triggers the problem, I have no idea what else to do to help narrow down the issue.

Hmm, now this is either odd, or embarassing. I just tried reverting back to a restore point from before I updated all those mods, and loaded in with the older version of the modpack just fine. Jumped on my train (which was already built then), and I didn't get far before it unloded the main train part again, and kicked me off the train.

Sometimes, only some of the carriages unloads, sometimes just the main train, sometimes the entire train.

We did also switch from Fabric to Forge back then, because Create was halting behind with very important bug fixes that we needed. I actually can't remember how much we played after the switch, as I remember it being a pain and taking a week+ to do.

It is very possible that this issue appeared after that, which limits the amount of mods that could be causing the problem, if not Create itself. After all, the Fabric version was several versions behind, so it is possible this problem got introduced in newer versions, but that is just a guess.

This is the list of mods that we added/exchanged (apart from updates for stuff like Create) - so that is some of what I will be messing around with. If I learn anything new, I will get back to this.:

Forge Version alternatives:

Continuity -> Midnighttigger's Default Connected Textures
Couplings -> Double Doors
Crawl -> Crawl on Demand
Discontinuous Beacon Beams -> FeyTweaks
Dynamic FPS -> FPS Reducer
Indium -> Lazurite + Forgified Fabric API
Inmis + InmisAddon -> Traveler's Backpack
Iris Shaders -> Oculus
Lithium -> Canary
More Culling + More Culling Extra -> Cull Leaves + MidnightLib
Reacharound -> Bridging Mod
Reese's Sodium Options -> TexTrue's Embeddium Options
Sodium -> embeddium
Sodium Extra -> Rubidium Extra + E
Trinkets -> Curios API
Universal Graves -> GraveStone + Death Backup + Soulbound Enchantment?
YOSBR -> Default Options
Forge Version New Mods:

Aether
Alex's Mobs + Citadel
Deeper and Darker
Enlightend
Modern Fix
Nether Dungeons
Our Villager Discounts
Very Many Players
Void Totem

cannot reproduce, likely caused by another mod or just server lag/network issues

This is most likely the server not being able to keep up or some other mod, steam n rails doesnt do anything that would cause this