In this case Strip END and ActionClip End are the same because the strip and clip start at 0, but the STRIP end is a global END value, if you move the strip to say start at frame 10 the Strip end will 110 but the Action/Clip length is still 100.

so what the point to have the same thing, if we look to the panel title,action's END must tweek the end of action keyframe position and start make the hole Kfs move like we have in strip panel: FRAME START, END.

That is what I am saying, they aren't the same thing

They are related, they adjust the same thing but one is global time and one is local time.

yahh, so it's a bug here

The action has it's own custom start and end range now but that is only when you create the clip from the action that has the custom range,
This Action Clip start-end can be any length you want but then if you move the clip , the end frame on the ACTION CLIP should stay the same, and the Strip End should change.

It isn't a bug unless that isn't happening

i think maybe i misunderstand the usage of actionstrip , especially for end frame

I can make a quick example video later to make sure it is clear. ...It was worse in last blender when End frame SCALED the clip but now just changes the end of the frame, but the names being the same was something that bothered me as well but we didn't have a better one and it was a lot of change already.

yes please; hope it will become better and clear

Hope this helps
https://vimeo.com/riggingdojo/nlastripvsclipstartend

thank you very much