Top left corner artifacts when launch MPV

[advice2020]

Linux Debian based distro / GTK based Desktop Environment
MPV 0.39.0
Using SSD (users using NVMe drive may not notice this due to increased launch speeds achieved)

Was wondering if anyone would be willing to confirm something / possibly know a solution to correct this?
I noticed that artifacts appear in upper left hand corner of screen depending on what viewing mode is used in MPV.

FLOATING WINDOW MODE
If you open up a video format file in floating window mode then no artifacts occur.

MAXIMIZED WINDOW MODE
(In mpv.conf use window-maximized=yes)
If you set to open media maximized then you will notice strange artifacts that occur in upper left corner of your screen.

If you snap your file manager to right side of screen and then open a video file from it, in upper left corner of screen flashes a rectangle window that shows a clipped portion of file manager file pane, showing the list of files that that media file was run from (in the Thunar that is snapped to right side of screen).
Then the video file is opened in maximized MPV window as expected.

FULLSCREEN MODE
(In mpv.conf use fs=yes)
A similar but different artifact occurs when opening media in fullscreen mode.

If you are in your file manager and you hit "Enter" key on a media file (associated with MPV application) then you may notice in upper left corner there is a small square box (approx 1.5 inch in size) that flashes before the application/video is opened in fullscreen. This might appear as just a black box is the MPV OSC is turned off, or will be a mini windowed version of MPV that shows the MPV OSC (GUI controls bar usually found at bottom of MPV)
Then the video file is opened in fullscreen as expected.

Visually these issues are not appealing / kind of distracting.
If anyone is willing to try this / has any information to share about this topic please let me know.

Thank You