AnimationPlayer unexpectedly toggles visible on calling advance and pause repeatedly

[jackycute]

Tested versions

Godot_v4.3-dev4

System information

Godot v4.3.dev4 - Windows 10.0.19045 - Vulkan (Forward+) - dedicated NVIDIA GeForce RTX 2070 SUPER (NVIDIA; 31.0.15.3713) - Intel(R) Core(TM) i7-3770 CPU @ 3.40GHz (8 Threads)

Issue description

I used AnimationPlayer.pause() to pause the animation when user stop moving the mouse and resume playing from the same frame when user interact again.
It works perfectly with Godot_v4.3-dev3 but in Godot_v4.3-dev4 it flips visible unexpectedly, thus I only can use speed_scale = 0.0 or seek to let it stop in the current playing frame without changing the visible.
(maybe related to discrete tracks?)

Steps to reproduce

Create an AnimationPlayer with a track that toggle any sprite visible back and forth and make sure it doesn't have any track set "Autoplay on Load".
Assign current_animation with the track and calling advance and pause in _process to step the animation.
Run the scene and you will find the result animation is different from the animation you see in the editor.

Minimal reproduction project (MRP)

animationplayer_pause_issue.zip

[TokageItLab]

Probably duplicate of #89322, fixed by #89329

[TokageItLab]

I confirmed #89329 fixed this.

However, the behavior of <| play_backward looks strange, but that behavior has been the same since the beginning of 4.0, so it does not seem to be related. It would be possible to make a separate issue about that.