easymotion-overwin makes errorbells

[draftman9]

I map s (easymotion-overwin-f2)
When I use "s" in the single windows, the annoying errorbells happen the same time when the markers appear. However the bells dissppear after I have had more than one windows.
My guess is that the problem exists as a result of "overwin" because the plugin runs well when I use "bd" motion. I hope that I can use "s" of "overwin" in any situation no matter when there is a single window or 2 windows. I hope "s" can adjust itself to the current situation.
I'd appreciate if you can fix my little problem.

I use gvim on win10. The info about version is VIM - Vi IMproved 8.2 (2019 Dec 12, compiled May 2 2021 19:00:02).