Loans expiring too fast

Hi!

I've used Adobe Digital Editions for loaning e-books for a couple years now during my university studies and it has usually worked fine. Recently my loans have been expiring almost immediately as I've downloaded them. That didn't happen before.

I usually loan the books from EBSCO database as a pdf file and select the option to loan them for 3 days. The downloaded file has a file extension ".acsm". I'm able to open and read the book for that period as long as I don't close the book in ADE. If I close the book the loan expires in under 15 minutes.

I tried to update to the newest version of ADE, but it didn't seem to help.

I'm running Adobe Digital Editions on Macbook Air (13-inch, 2017) and macOS High Sierra v. 10.13.6.

Regards,

Tino