Razer Naga Chroma B4/B5 remapping broken after Synapse 4 update
Device: Razer Naga Chroma RZ01-01610 / RZ01-0161
OS: Windows 11
Synapse 4: 4.0. [removed by moderator]
Firmware: 1.0.3.0
I am having a reproducible problem with the B4 and B5 buttons next to the scroll wheel on my Razer Naga Chroma.
These buttons are originally programmed as Sensitivity Stage Down/Up.
I want to use them as:
B4 → Mouse Button 4
B5 → Mouse Button 5
This worked correctly with older versions of Razer Synapse.
However, after a recent Synapse update, the remapping no longer works correctly.
Current behavior with Synapse 4 running
Synapse shows:
B4 = Mouse Button 4
B5 = Mouse Button 5
But the actual buttons still behave as their original Sensitivity Stage/DPI buttons.
Pressing B4/B5 changes the DPI and the DPI popup appears.
The assigned Mouse Button 4/5 function is not properly applied.
I also noticed that when editing B5, Synapse identifies it internally as “Sensitivity Stage Up”, even though the selected Mouse Function is Mouse Button 5.
Important test: Synapse completely closed
When I completely close Synapse 4 and verify that the Synapse/RazerAppEngine processes are no longer running:
B4 works correctly as Mouse Button 4
B5 works correctly as Mouse Button 5
Back/Forward works correctly
The DPI popup no longer appears
B4/B5 no longer change DPI
Other custom mappings that require Synapse naturally stop working when Synapse is closed, but B4/B5 continue to work as their native Mouse Button 4/5 inputs.
This strongly suggests that the problem is caused by Synapse 4 intercepting/overriding the B4/B5 buttons incorrectly.
Troubleshooting already performed
I have already tried:
Multiple Synapse 4 reinstalls
Clean profiles
New profiles
Guest mode
Deleting profiles
Razer Driver Cleanup Tool
Removing Razer devices/drivers through Device Manager
Synapse Repair
Restarting Windows after each relevant step
Synapse 4 installation without Cortex
Sensitivity Stages disabled
Hypershift ruled out
Compatibility Mode disabled
Checking RazerAppEngine in Task Manager
Mouse-button testing software
Synapse 4 Beta
The Synapse 4 Beta has exactly the same problem.
I also found an old “Razer Synapse Service” Windows service pointing to a missing Synapse 3 executable. I removed that stale service registration and restarted Windows, but it made no difference.
Most important evidence
The same Naga Chroma worked correctly with older Synapse versions.
The problem appeared after a later Synapse update.
The exact same hardware works correctly when Synapse is completely closed.
I have also tested a Synapse 4 Beta and the issue remains unchanged.
Request
Can Razer please investigate this as a possible Synapse 4 regression affecting the Naga Chroma B4/B5 Sensitivity Stage buttons?
In particular, I would like to know why Synapse 4 continues to treat B4/B5 as Sensitivity Stage buttons even after assigning them to Mouse Button 4/5.
This is not a hardware issue or a simple profile/install problem, as the same mouse and buttons work correctly when Synapse is closed and worked correctly with older Synapse versions.
Please escalate this to the Synapse 4 development/engineering team if possible.
Has anyone had this problems?
