Laravel validator Mimes SIZES not working

Hello,

When I upload a file with vue and try to check it with the Laravel validator using:

            $validator = Validator::make($request->all(), [
                'file1' => 'nullable|mimes:jpeg,png,jpg|max:500|dimensions:max_width=400,max_height=400',
            ]);

            if ($validator->fails()) {
                return response()->json(['errors' => $validator->errors()], 422);
            }

I tried to upload a file as big as 2.5 meg and also with dimensions of 600 x 400 px, they all pass through.

Any idea why please?

Thanks