I have the same issue.
It costs $377 to change the shutter button. Sony refuses to recognize this issue. As least with me they claimed there was no known issue and since my camera was out of warranty I had to pay for the repair. I pointed out I know of some people who had their A7c shutter button replaced for free outside of warranty even without a formal recall due to the ubiquity of the issue. The person I spoke to said this is impossible and refused to connect me to a supervisor or say anything other than the camera is fine and that I am the only person who ever had this issue.