QBO receives the raw data from either PayPal or from your banking institution, TBLS Treasurer.
Can you tell us what happens when you change the account? Do you still see the Split button? We just want to make sure that we're giving you the most accurate information about this.
In the meantime, you can temporarily log out of your account. Then, log back in using a different browser. QBO is compatible with Google Chrome, Mozilla Firefox, Microsoft Edge, and Safari.
Once done, go back to the downloaded transaction and check if you can change the account or make the changes.
Aside from that, I'd suggest reaching out to your bank or PayPal, depending on how the transactions are downloaded. They can check why the net amounts are now showing as fees.
The Community is always here if you need anything else.