Gamemode core pinning

I've previously configured gamemode to pin games to my 3D cache cores on my Ryzen 9 7950X3D CPU. However, recently I haven't been able to get this to work. Games seem to span all cores (based on core usage) and I'm experiencing mild stutter in some games that are known to suffer from this on these types of CPU's.

I tried on 2 different distros. Arch and Fedora.

I have the "pin_cores=0-15" option set in in /etc/gamemode.ini file. When running gamemoded -t I get the following:

: Loading config
Loading config file [/usr/share/gamemode/gamemode.ini]
Loading config file [/etc/gamemode.ini]
Config: Value ignored [general] disable_splitlock=1
Config: Value ignored [cpu] pin_cores=0-15
: Running tests

:: Basic client tests
:: Passed

:: Dual client tests
gamemode request succeeded and is active
Quitting by request...
:: Passed

:: Gamemoderun and reaper thread tests
...Waiting for child to quit...
...Waiting for reaper thread (reaper_frequency set to 5 seconds)...
:: Passed

:: Supervisor tests
:: Passed

:: Feature tests
::: Verifying CPU governor setting
::: Passed
::: Verifying Scripts
::: Passed (no scripts configured to run)
::: Verifying GPU Optimisations
::: Passed (gpu optimisations not configured to run)
::: Verifying renice
::: Passed (no renice configured)
::: Verifying ioprio
::: Passed
:: Passed

: All Tests Passed!

The "Value Ignored" during the test seems to indicate that the setting isn't being applied.

Has anyone faced a similar issue?