I then stumbled onto a post which I found very helpful:
''When inserting [WholeNumber].025, it calculates to 0.99... which doesn't mathematically make sense based on what they claim the fee to be. Also, if you try [WholeNumber].026, it calculates to 1.001.
To get your NEO out, you have submit [WholeNumber].025000001 for it to calculate to a whole number for withdrawal. Wanted to share for others having same problem''
Credits to the author of the original link I found hope this helps you as much as it did me!
https://www.reddit.com/r/NEO/comments/6w5auf/solution_for_those_who_cannot_withdraw_from/