[issue] bfi and subframe insertion works at half the framerate.

Is there an existing issue for this?

• This is a bug in RetroArch frontend
• I have searched the existing issues

Description

in the latest stable version of retroarch, on windows (1.22.1)
it seems bfi and subframe insertion work at half the framerate.
i mean by that is , when i set to 100 120 140 hz
it seems to work at the game framerate instead so 50 60 and 70
and add black frames still so the shader works at 25 30 and 35 frame by sec
and because of that the screen blinks a lot
im using a amd 5700xt and a freesync premium monitor at 165hz.

Expected behavior

it should work at 100 120 and 140hz
with a black frame at 50 60 and 70hz

Steps to reproduce the bug

enable subframe shader
enable exact framerate
use crt beam simulator shader
run a game.

Version/Commit

1.21.1

Bisect Results

No response

Present in the nightly version

I don't know

Platform & operating system

windows 11

Affected Cores

No response

Environment information

No response

Relevant log output

No source file or test is identified. Start by reproducing the issue on Windows 11 with the subframe shader, exact framerate, and CRT Beam Simulator at 100, 120, or 140 Hz, then trace the frontend's black-frame timing and compare it with the expected doubled refresh rate. Done means black-frame insertion runs at the configured display rate without blinking.