In the MoonBot terminal, in the strategy settings on the Filters / Base tab, there is a parameter called MaxLeverage (maximum leverage) that determines the maximum leverage for coins to be included in the strategy. If the leverage on coins is higher than the specified value, the strategy will not include such coins. If the IgnoreFilters = YES checkbox is selected on the Filters tab, this filter will not work and all coins will be analysed regardless of the set leverage. By default, the MaxLeverage parameter is set to 0, i.e. the filter is not limited by the maximum leverage. In your case, you need to set IgnoreFilters = NO and MaxLeverage = 20, then coins above the x20 leverage will not be considered by the strategy.
To ensure that this parameter is checked by the strategy, you need to set IgnoreFilters = NO on the general Filters tab, and IgnoreBase = NO on the Filters / Base tab. A green vertical bar should be visible to the left of the Filters / Base tab, indicating that this tab and the parameters in it are not being ignored.