This sounds like a problem with the dial’s encoder rather than a setting issue. One plausible cause is dust/debris interfering with the encoder, especially if the dial sometimes works and sometimes skips.

Based on the advice given, more contact cleaner is not a great idea. If the encoder is optical rather than a simple exposed electrical contact, cleaner may not help and could mix with dirt, making the problem worse. On a weather-sealed body, spraying fluids into the control area also risks introducing contamination where it shouldn’t be.

The safest thing to try is gentle air cleaning around the dial to see if debris can be dislodged. If that doesn’t improve it, professional service is the sensible next step. Since no one provided actual Canon repair pricing, there’s no reliable way to estimate the cost from the information here.

In short: stop using contact cleaner, try careful air cleaning, and if the skipping continues, send it to Canon or a qualified repair shop.