Validation Group not working for file component

ValidationGroup is not working as expected, when applied against a file component. It is validating entire form and not restricted to fileUpload component only. 

Requirement: When user clicks on "Upload File" button it should only validate file specific validations.

PS: I did try setting Validate: false for button component. But it did not work. 

Thanks for help in advance

a!fileUploadField(
labelPosition: "COLLAPSED",
target: tofolder(ri!appianFolderId),
instructions: "Please click on ''Upload File'' button to upload the file in system",
validationGroup: "UPLOAD_VALIDATE",

validations: {
if(
and(
a!isNotNullOrEmpty(fv!files.extension),
contains(cons!VALID_FILE_EXTENSIONS, upper(fv!files.extension))
),
"",
"File extension is not supported"
),
if(
fv!files.size > cons!FILE_SIZE,
"Attachment file size is more than 10 MB",
"",

),
},
value: ri!uploadedDocument,
saveInto: {
ri!uploadedDocument
},
maxSelections: 1,

),
a!buttonArrayLayout(
buttons: {
a!buttonWidget(
label: "Upload File",
style: "SOLID",
submit: true(),
validate: true(),
validationGroup: "UPLOAD_VALIDATE",
disabled: a!isNullOrEmpty(ri!uploadedDocument)

)
}
)