Perfectly balanced GH5 on my Ronin S. Settings are right - without camera the infinity spin works, even if it look not very stready. When I put my GH5 on the Ronin-S it tries to do the spin, but after about 90 degrees it stops and the gimble goes crazy.
Sorry to read on your post, may I verify your settings? After the physical balance, please try the Auto Tune and then tilt the device 45° to check if the Power value of the Pan motors is in the range of +/-5. If not, the device will need to be balanced again.
I see, checking if the power value of Pan axis is within +/- 5 is more precise to confirm the balance status, besides, may I have the screenshot of the “Configuration”---”Control Settings”--- “Channels”?