I submitted a question to this board for this exact same issue before finding this post. I filed a dispute with PayPal under "billing" issue because none of the other categories seem to make sense--PayPal denied my claim because it's considered "not a billing issue" without rerouting me or trying to resolve. It seems like a straightforward issue so it's pretty frustrating to need to jump through hoops to get it corrected.
EDIT: elsewhere on the internet, others are complaining too--it's looking to be a PayPal issue which they're refusing to address? SHADY.
https://www.reddit.com/r/Aliexpress/comments/jhympw/cash_advance_fee/
EDIT2: I reached out to AliExpress, and they say they didn't change their payment methods on the backend so to take it up with PayPal, who is also not taking ownership. I called my credit card's affiliated bank (Chase) again, and the rep waived the fee for me this time--I have good credit history and have been a customer for 10 yrs so YMMV. Also, my previous call to Chase was unsuccessful so you might need to call a few times and hope to catch a nice rep. Good luck to everyone except PayPal, who NEEDS TO STEP UP WITH THEIR CUSTOMER SERVICE.
