3 steps undo only

@petr_4395 

Don't have this problem at all - and only 16GB of RAM:

Can close and open History panel without resetting it.

And can jump back and forth to any state.

Maybe your file is corrupted? Try what @Mike Witherell suggested - start from IDMLing then resetting preferences.

Is this happening on a same file you are sharing?

You might experiment with some of the troubleshooting here, including resetting InDesign preferences.

The numberof undos depends on free ram, free working space on disk. 
if many programs are running or if the amount of used content in the clipboard. 

Hi @petr_4395,

Thanks for sharing the setup details. Could you describe a bit more about what’s happening with the undo issue? For example, is it that InDesign only allows you to undo three actions and then stops? Does it happen across all documents or just specific ones? Also, do you notice if this starts after a certain action or plugin use? If possible, share a screen recording demonstrating the workflow till the issue. 

Looking forward to your update!

Abhishek