Emulator

Game Name?

Any

What's the problem? Describe what went wrong.

Using the settings below, toggling fast forward by tapping/releasing the TAB button, quickly interrupts the emulation to show the frame that was rendered when going fullscreen.
Video here (recorded on phone because the problem wasn't shown with a screen recorder): https://photos.app.goo.gl/yGq4Gf2uGD7rz4Ff6
(I also set the backlash button to toggle fullscreen for easier recording)

What steps will reproduce the problem?

Video backend: Vulkan;
Vsync: On;
Play any game, toggle fullscreen (both borderless and exclusive have the problem) and press TAB: you will see the problem.
Something is still wrong even on windowed though: mashing TAB slows down the emulation, which doesn't happen with a different backend and/or Vsync off.

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 (12528).

Is the issue present in the latest stable version?

Didn't test.

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.)

Didn't test.

What are your PC specifications? (CPU, GPU, Operating System, more)
CPU: AMD A10-9700
Video Card: AMD RX 460 2GB (drivers: Adrenalin 20.8.3, the latest)
OS: Windows 10 2004