Are you shooting RAW or .JPG?
If you're shooting JPG you might need adjust the in-camera "Sharpening" setting. This might be a good test to run, even if you primarily shoot RAW. Switch to, and then shoot, some JPG files and see what you get once you've adjusted the sharpening in-camera.
To check/adjust the setting, go into the Shooting Menu (camera icon), highlight "Set Picture Control", right-click once using the four-way button and highlight whatever setting you use here (Standard, Vivid, whatever). Right-click one more time and drop down to highlight the "Sharpening" setting and move the slider to +7. Be sure to press "OK" to save the adjustment.
.....