There is currently a global issue where the skip condition isn't working properly when using the "By Field" option with a dropdown field. Our developers are aware of the problem and are working on a solution, but it may take some time to fix.
In the meantime, there is a simple workaround. To make the skip condition work, remove any leading white spaces from the text entry fields of your dropdown options. This is important because it's easy to accidentally add a space when listing options, which can cause an issue.
By removing the extra space, the skip condition should function as expected.
To make things clear see sample screenshots below for reference.
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