If you only use continental signal-systems of Europe you can fix it.
edit the config.txt of all the engine-specs you use in a session and add the line
"autopilot-caution-speed-multiplier 1"
this works for electric engines, diesel engines and rolling stock but not for steam-locos
Austrian and Italian Route (1GB)
https://www.trainz.de/download/file/138-brennerbahn-ferrovia-del-brennero-v1-0/
https://www.youtube.com/@brennerbahn-laferroviadelb9179/featured