Hi Erik,
The value transferred via Lookup field transfer didn’t automatically cleared when the lookup value is removed.
Please see the sample below:
Applying the lookup value ([C] Printing Plate No.) and corresponding fields ([C] Logo Name – Internal Description, [C] Logo Name – External Description) values are applied.

Removing the lookup value ([C] Printing Plate No.), but the corresponding fields’ value stays intact.

Regards,
Kevin
hougaard Answered question 2 days ago
That’s how the transfer field works. Values are transferred when selecting a new value. If blank is selected (and that’s not a value), then nothing is transferred.
The alternative is to create a FlowField (subtype Lookup) to always pull a value based on the current content of the lookup field.
hougaard Answered question 2 days ago