Frequent admin password prompts

I recently installed BitDefender Total Security 2018 on a number of computers.  The users on these computers are standard users - not administrators.  Very often, these users will receive a prompt for administrative credentials from "Bitdefender SRL".  I assume this is BitDefender trying to update itself, and failing because it requires admin credentials.

Is there any way to resolve this?  It seems crazy to me that an antivirus product would require users to be local administrators on their workstations in order to successfully update.

Interestingly, I had the free product installed on these machines before switching to the paid version, and I never had this problem with the free version!

I've attached a photo that one of the people using the workstation with the product installed sent me.

Thanks in advance for any help!