On 1.21.3 Forge Powered Rail are working like Activator Rail, so it is impossible to do railways.

[Lbtn]

When you are placing a minecart on Powered Rail, it is starting shaking and dismounting a player, instead of speeding up. (Without forge everything is ok, no mods installed)

[c4dx]

Bump.

Just ran into the same problem.
Also tested the activator rail for switched functionality, unfortunately not. They are both just acting as activator rails.

Any solution to this or do I have to try to switch versions for everything?

[c4dx]

  On 11/6/2024 at 10:12 PM, Lbtn said:

When you are placing a minecart on Powered Rail, it is starting shaking and dismounting a player, instead of speeding up. (Without forge everything is ok, no mods installed)

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Go it working again.
 

Forge -> Select your game -> 3 dots on the right -> Profile Options:
I've raised the modloader version here to 53.0.11

Disabled all mods (libIPN, Inventory Profiles Next, JourneyMap, Kotlin for Forge)
Noticed its working again.
Switched on 1 mod at a time until on were on.

Bug's gone.

Hope it helps.

[LexManos]

https://github.com/MinecraftForge/MinecraftForge/commit/e2a68ad903e09604c3754a65cb1b0c8db72ae308
It was just a misapplied patch, update forge and you'll be fine.