Emulator

Game Name?

Luigi's Mansion

Game ID? (right click the game in the game list, properties, info tab)
GLME01

MD5 Hash? (right click the game in the game list, properties, info tab, MD5 Hash: Compute)

6e3d9ae0ed2fbd2f77fa1ca09a60c494

What's the problem? Describe what went wrong.

In Luigi's Mansion, there is a mirror specifically located in the 1st floor washroom (The room with Toad where he loses his keys in the toilet). This mirror is broken, and apparently has been broken for many years across several builds after doing a lot of research into this issue. The mirror's render is off center and warped. The mirror moves around with Luigi as Luigi moves. Looking at the mirror in first person also changes the distortion. You can see the black void/skybox through it.
OTHER MIRRORS APPEAR FINE as far as I am aware!. Please check THIS mirror specifically to see the glitch.

What steps will reproduce the problem?
Simply enter this room, the 1st floor washroom, and check the mirror on almost any 5.0 dolphin build. Issue happens in 5.0-8849. Just have access to this room and check this specific mirror. Walk around it. This happens on any GPU backend + adapter. This happens regardless of settings/hacks.

Is the issue present in the latest development version? For future reference, please also write down the version number of the latest development version.
Yes.
Dolphin 5.0-8849

Is the issue present in the latest stable version?

Yes.

If the issue isn't present in the latest stable version, which is the first broken version? (You can find the first broken version by bisecting. Windows users can use the tool https://forums.dolphin-emu.org/Thread-green-notice-development-thread-unofficial-dolphin-bisection-tool-for-finding-broken-builds and anyone who is building Dolphin on their own can use git bisect.)

I don't know how far back this goes, but I have found this issue being reported as far back as 2015 on the forums.

If your issue is a graphical issue, please attach screenshots and record a three frame fifolog of the issue if possible. Screenshots showing what it is supposed to look like from either console or older builds of Dolphin will help too. For more information on how to use the fifoplayer, please check here: https://wiki.dolphin-emu.org/index.php?title=FifoPlayer

Fifolog attached.
Luigi is standing in front of the mirror. The mirror's render is incorrect. It's raised up and slightly warped/skewed/titled. It is not supposed to be.

What are your PC specifications? (CPU, GPU, Operating System, more)

CPU: i7-8700k
GPU: NVIDIA GTX 1080
OS: Windows 10

Is there anything else that can help developers narrow down the issue? (e.g. logs, screenshots,
configuration files, savefiles, savestates)

This issue only affects one specific mirror in the game as far as I know. There may be others I have not found yet.
Screenshots attached
Video attached
Fifolog attached
Savestate uploaded to: http://www.mediafire.com/file/172cu79y24ju9jq/mirrorwashroom.sav/file