QML merges all parameters from a JS function in one when saving

QML rewrites this code:

function textValueToBackEnd(fieldName, value)

{ Supplier.SupplierType.textValueToBackEnd(fieldName, value) }

TO

function textValueToBackEnd(fieldNamevalue) { Supplier.SupplierType.textValueToBackEnd(fieldName, value) }

when saving  the changes.
Workaround: In options > Qt Quick > Uncheck "Enable auto format on file save"

I've been using 5.12.1 without problems but I'm facing this issue after updating last week.
I reinstalled Qt 5.12.4 and also Qt 5.13 but qml still rewrites the parameters of my JS functions.