Im pretty sure im too late but i had transferred 10,000 ecodollars from my bank to to skyblock server and and only got around 600 i didn't think about doing anything about it till later i had things to do and i spent it is the only thing i can do is wait and see if it happens again and report it when it does.
When you withdraw money from the bank onto skyblock the transfer rate is 15:1. So for every 15k you withdraw from the bank, you'll only get 1k on Skyblock. Which is why when you withdrew 10k, you only got $600.
The current withdrawal rate is 15:1. This will be changed to 10:1 very soon. Ultimately, during the next SkyBlock reset, the rate will be adjusted to 1:1 and the prices will be adjusted to match the main server.