How can I choose whether to perform a full or incremental backup for a maual backup in 12.5

The release notes for Backup 12.5 Update 1 indicate that for a manual backup (no schedule defined) you can now choose whether to perform a full or incremental backup but I cannot figure out how to do this.

Test Performed: Install Backup 12.5 Standard, Build 7970. Define a backup plan with no schedule. Perform a backup. The first time I perform a backup it performs a full backup. Thereafter, the "backup" button is supposed to be a drop-down list that should allow me to choose either "Full" or "Incremental". However, I have no such options. When I choose to run a backup again it seems to create an incremental backup (based upon the small size of the backup).

How can I perform a new full backup or get the option to choose what type of backup I want to perform?

Note: I have not been using Acronis Backup extensively, so if I'm simply overlooking something obvious please feel free to point this out, but I've been digging through the app pretty extensively and looked through the docs, knowledge base, and forum and still have not been able to figure this out.