You have stated that"name differs from my signature in the online form."- But the main criteria is - is your signature on the online form also the same one you use elsewhere normally? If that is so, then you need not worry. Any other documents which are compared for the purpose should also have the same signature.
Though itis preferable to have the signature giving hints of the name, practically it is not always so. Some people have their signature only as some wavy lines or dots with a few alphabet etc. The main point is that the pattern should be always uniform. The size and ratio aspect may change according to the size of the paper, the pen or pencil used, the comfort and space you get for signing etc. A larger size signature will also be in the exact pattern as the small size signature. When we get to sign on a blank paper, we get more ease to sign than to sign inside a box. However both will have same pattern. That is called uniformity. It is this uniformity that is essential.
However if you have not signed the way you already signed elsewhere(offline) to this same purpose, then you may need to justify or correct it later, if both are compared and difference found.