Two monitors do not necessarily need the same refresh rate. One can operate at a supported higher rate while another remains at 60 Hz, provided the host, connection paths and workload support the combination. Select and verify each display separately rather than assuming that the first visible setting applies to both.
Identify the screen before changing its mode
Use the operating system's display identification and advanced display controls to select the intended physical monitor. The settings route varies by version, so check that the monitor name or number matches the screen being adjusted. A change made to the wrong display can appear ineffective while silently altering the other one.
Review available modes together with resolution. A high refresh option may appear only at a lower resolution or with another supported signal configuration. The absence of the advertised maximum does not by itself show that the monitor is defective. An adapter, cable, dock, host limit or another display sharing the route can constrain what the system offers.
Apply a documented supported rate and use the confirmation mechanism to preserve or revert it. If the picture becomes unstable, return to the known-good mode rather than repeatedly forcing an unsupported combination. Keep the original setting recorded so testing does not depend on remembering which of several similar values worked earlier.
Test the workload, not only the menu
Move windows, scroll ordinary content and run the applications that matter. Higher refresh can improve the feel of motion, but it does not automatically improve every task or resolve input latency elsewhere. A text-reference screen may serve its purpose well at a modest stable rate while the primary motion-focused screen uses a higher one.
Check the combined arrangement with normal video playback, calls or graphics work where relevant. Mixed-refresh behavior can vary by graphics driver, operating system and application. Avoid presenting one past problem on one platform as a universal rule that all monitors must match, or one successful desktop test as proof that every workload will behave identically.
If another screen disappears or a mode drops after raising refresh, inspect the shared capacity and host configuration. Each monitor can work alone while the combination exceeds a supported limit. Lower one demand temporarily to test that hypothesis, keeping other variables unchanged and recording the result before drawing a conclusion.
Choose the final rates according to supported capability, stability and the user's actual priorities. Save the values with resolution and connection routes, since a dock or driver change can alter available combinations. The aim is a reliable two-screen workspace with useful motion characteristics, not matching numbers for their own sake or maximizing a setting that adds little value to the task.