Hi @michal.mendyk 

Ok its a bit of a complicated configuration you are trying out here, you have both GTIN, GS1 and BARCODE_ID (which is IFS own inventory part barcode) and you are using the BARCODE_ID inside the GS1 but not GTIN inside the GS1 (which would also be possible I would guess).

A bit strange why you have then GTIN after PART_NO since the 2 values you could get from GTIN is PART_NO and INPUT_UOM, with your setting here you are just getting the INPUT_UOM from GTIN, but maybe you are using it to verify that you are scanning/picking the correct Part, I'm not sure why else you would do this?

And BARCODE_ID main purpose is to identify both PART_NO, SERIAL_NO, LOT_BATCH_NO, CONFIGURATION_NO, ENG_CHG_LEVEL, WAIV_DEV_REJ_NO and ACTIVITY_SEQ, but looking your configuration you don’t seem to use it to get the first ones anyway,  only last 3 items can be fetched from the BARCODE_ID with that configuration, maybe you are not using serial/lot batch/configuration parts in your warehouse so they don’t need to be fetched from the BARCODE_ID. So is this also just to verify that you are scanning and working with the previously selected Part?

Plus having unique_line_id this late in the flow could be bad for the performance since its the real pick list line record key, its for a reason early in the template configuration, plus its template position and settings are there to give a guided flow controlled from the pick list order, like it tells you which part and location to pick/go-to, that you now will loose.

But back to your original question, I'm not sure, you could perhaps also have GTIN fetched from GS1 barcode so both GTIN and BARCODE are controlled by an Application Identifier, but I would guess your main problem would still exist and you would still have to manually press save on the one you don’t want to use. 
One solution could be to have 2 different configurations, one that use GTIN and one that use BARCODE_ID if that is possible in your situation, you could have menu label names that would indicate that its for GTIN or QR. 
I don't see any other current configuration settings you could do to support your scenario, or else you could do a code customization for this specific scenario, if you set Use Automatic Value to Fixed on BARCODE_ID you could change inside the automatic logic so if GTIN have a value it could skip BARCODE_ID (by returning the string 'NULL') it might require some other changes also to avoid the current handling of how BARCODE_ID works.

Hello @Dario Zani 
Our full flow currently looks like this (for Picking Items with Supply Code “Invent Order” (stocked products)):
Scan the QR code on Customer Order Label to fetch the Picklist No.
This is done by the START_PICKING configuration

Then from the REPORT_PICKING_PART configuration, user can choose which picklist line to process.
 

Next step is to scan Inventory Location Label, then based on the product user will either scan GTIN Label or Part No Label to get BARCODE_ID value (if the GTIN is not available). Last step is to type Qty of products to pick, press “Save” and choose next Pick List Line to process. 

My main idea was to keep this process under one WaDaCo configuration, so users are not forced to swap between two picking options on RF Devices. The GTIN screen will appear always on RF Device and BARCODE_ID visibility will rely on the GTIN value (hidden if GTIN was scanned or visible if GTIN Value is NULL)

Also thank you for the recommendations, I will do some changes and test the configuration.