I found something that may help.
https://www.paypal-community.com/t5...yet-paypal/td-p/311266?profile.language=en-gb
It's couple years old,but it may shed some light:
------------------------------------------------------------------------
Hey guys,
As part of our payment holds for new eBay sellers, we'll hold the money from your eBay transactions for up to 21 days. The funds for payments received are held temporarily as a pending balance in your account. New sellers on eBay are sellers who received payment for their first eBay sale less than 90 days ago.
Your funds will be released within 24 hours from when one of the following occurs:
The buyer leaves you positive feedback
21 days pass without a dispute, claim, chargeback, or reversal being filed on the transaction
You provide a tracking number which shows that the item has been delivered over 3 days ago
----------------------------------------------------------
If you ship it and it gets delivered it looks like they will release the funds in 3 days.
I am guessing this is for new(er) accounts.