Help, Unity 2D Animation Shows Completely Wrong Sprites (Breaks?) After Build. (Maybe only with transitions)

I’m very new to Unity and have been following a tutorial guide to create a very simple 2D game. Everything worked fine until I built and ran the Windows/Web version of the game.

In the editor (Game View), my 2D sprite animation works fine. However, after building the game (Windows/WebGL), the animation starts using incorrect sprites from other textures.

Video Example:

In Editor:
(Wanted to add video here but forum won’t let new users post two videos at once huh.)

After Build Runtime:

The three figures below use the exact same animations as the player character (Run-Jump-Landing). However, as you can see, the animation completely breaks only after the build. I think it seems to happen only during animation transitions, but not sure.

I tried deleting and recreating all animations and sprite files (including meta files), but nothing changed.

Are there any basic things I missed and I should look into?

In Editor View:

Hi,
Could you please post a repro project or a bug report? That would be helpful to analyze this issue better.
Thanks.