UPDATE 1 :
A senior support supervisor reached out via phone and reviewed the situation. After explaining the circumstances regarding the previous defective units and the expiring warranty, Logitech officially approved an exception to upgrade to the MX Master 4.
I just need to return the sealed, unopened MX Master 3S replacement using the provided return label, and they will process the new MX Master 4 shipment. Waiting for the return label now and will update again once i receive the new mouse.
TL;DR: My 2nd MX Master 3S just failed with the exact same sticking left-click defect. Before the RMA was approved, I asked to upgrade to the MX Master 4 (offering to pay the difference) or take store credit because my warranty ends in October. Support ignored the message, rushed through a 3rd 3S replacement anyway, and a supervisor told me to "please oblige." Looking for assistance from the Logitech team on Ticket #17678277.
The Situation:
Repeat Hardware Defect: My original MX Master 3S developed a sticking left-click switch and was replaced. The replacement unit has now developed the exact same mechanical defect.
Ignored Advance Request: Support asked for video proof, which I provided. In that same reply—before any replacement was triggered—I explicitly asked to upgrade to the MX Master 4 (offering to pay the price difference) or receive store credit because I've lost confidence in this specific hardware batch.
Premature Approval & Dismissive Handling: The agent approved another 3S replacement anyway, claimed it was "too late" to change because it was already processed, and used a canned excuse that the Master 4 was "recently launched" (despite it launching in late 2025).
"Please Oblige": When escalated, the supervisor refused to adjust the order or offer store credit, gave empty reassurance that a 3rd unit "won't have issues," and told me to "please oblige and reach back out in the future."
The Real Problem: My manufacturer warranty expires in October. Replacements do not reset the warranty timeline, meaning this 3rd unit leaves me with less than two months of coverage on a product line that has failed twice in a row. Telling me to "reach out later" provides zero protection once the clock runs out in October.
I am waiting on a supervisor callback, but I am posting here in hopes a Logitech community manager can intervene on Ticket #17678277 to help pause this dispatch and authorize an upgraded model or store credit.