jpeg signature file is now too large? and actually is bellow than 11 KB

I have been using the same jpeg image for my signature on previous versions of Acrobat Reader.  On the newest version the signature appears too large for any image document, always alert me that the image file is to large and select a different file smaller than 20 MB but the image that I selected is just a size by 11 KB. I'm using Windows 10 64 bits, please your help to solve this issue asap.

Thanks.