FPS drop when facing the map interior (even if only a wall is visible)

I’m experiencing a strange FPS drop in Apex Legends.
When I stand near the edge of the map and face toward the inside of the map,
my FPS drops significantly — even if the screen only shows a wall (from 200 down to around 100).

However, when I face toward the outside of the map (toward the sky or ocean),
the FPS stays high and stable, even with a wall in front of me.
It feels like the game is still rendering the entire interior of the map behind the wall.
In other words, it seems that occlusion culling (skipping hidden objects) or
frustum culling (not rendering outside the camera view) isn’t working correctly.

What’s even more confusing is that my GPU usage stays around 30–40%
and my CPU around 50%, so both still have plenty of headroom —
yet the FPS suddenly drops.
This doesn’t look like a hardware bottleneck, but rather an issue with
how the rendering load or draw calls are being managed.

In older gameplay clips when I used to play with the FPS capped at 144,
it was completely stable and never dropped below that.
Something may have changed in the game or driver settings since then,
causing this different behavior.

For reference, all in-game graphics settings are set to “Low.”
My NVIDIA Control Panel is also fully optimized for performance
(Power management mode: Prefer maximum performance,
Low latency mode: On,
Shader cache: 10 GB, etc.).

System:
RTX 3070 / i7-11700 / 240Hz monitor / G-SYNC On / FPS cap 200

Has anyone else experienced the same issue?
Or is there any known way to limit draw distance behind walls
or force proper occlusion culling in this game?