If you are running on DCC this is normal - it's all down to the setting of the acceleration CV.
If you have further problems on DCC let us know what control system & decoders are in use & post in the DCC forum (hard hats optional, but recommended !)
If you have further problems on DCC let us know what control system & decoders are in use & post in the DCC forum (hard hats optional, but recommended !)