When using the Feature Selection Filter node, with Include static columns and Select features manually enabled, there is a bug in selecting the feature set from the table.
It seems if the currently highlighted feature set is using n “Nr. of features” and then you select a different row with the same n “Nr. of features” and click OK, it says the settings were not changed and therefore the node will not be reset. It seems have to select a row with a different number of features, click OK, and then go back in again and choose the one you wanted. This is happening all the time for me.