Right Jim, your are in the correct area and what you observe is accurate.

the subtle difference is in the specification of the path. It is a UX issue.
in BIAB preferences you provide the complete path
C:\bb\RealTracks\
in Manager the nomenclature changes, RealTracks Folder location
you provide part of the path, just the parent folder
C:\bb\
there is an uncommunicated presumption that the install will create or use a subfolder named RealTracks.
^ This is the disconnect.

If your configuration has the n,nnn Gigabytes of RT & RD data on another drive this subtle change in folder spec can be confusing.

--- Scenario
Installed BIAB 12 months ago, two drive configuration C: & F:
Never change or look at the locations for a year while you enjoy making music.
Now Using Manager to Install and need to answer the Install Folder questions.
Before Pressing Install you want to get it right to avoid a messed up install
Go into BIAB preferences to see where the RT & RD are currently.
F:\bb_Real\RealTracks

See the 3 Install Folder questions on the right side are asking two different questions the green one is complete path, the RT & RD are asking for part path just the parent folder.
And these folder questions are different than the Preferences setting.

Attached Files (Click to download or enlarge) (Only available when you are logged in)
BIAB RT pref Screenshot 2021-12-05.jpg (55.33 KB, 27 downloads)
BIAB RT MGR Screenshot 2021-12-05.jpg (19.28 KB, 27 downloads)
Manager setting