Hi @DaddyXtof, thanks for the report. I spent a good while trying to reproduce this on Windows with neovim running under psmux and I could not trigger it.

I ran more than 160 cycles of entering insert mode and pressing Escape, including rapid Escape bursts, Escape immediately followed by another key, the Ctrl+[ alternative, and Escape right after fast paste style input. Escape returned neovim to normal mode every single time.

One thing worth noting: on Windows, psmux reads Escape as a discrete key event and forwards it straight to the program, so the escape-time option has no effect on this path. That option matters for the Unix style raw byte input where a lone Escape has to be told apart from an arrow key sequence, which is not how the Windows console path works. That matches what you saw when changing escape-time made no difference.

To help me pin this down, could you share a few details:

1. Does it start only after a specific action, for example after selecting text with the mouse, resizing the window, or switching panes or windows?
2. Roughly how long, or how many keystrokes, before Escape stops responding?
3. Does a brand new nvim --clean session with no psmux config also show it?
4. Your psmux version, your terminal (you mentioned wezterm and Windows Terminal earlier), and whether mouse mode is enabled.

For context, I just fixed a separate Ctrl key doubling bug (commit ba64598) that made neovim window commands misbehave. If your Escape trouble appeared alongside odd Ctrl behaviour, the next build may improve things. I will keep this open and keep digging once I have your answers.