Depending on how the instalation logic is set up what you see could be correct.
the installation could look for the folders needed on the drive.
Folders do not exist - flag is set to use the C: drive (target drive is presumed to not exist).
Folders need to be created - they use the drive specified.
Installation looks at the flag that states C: needs to be used and installs on C:
Next installation attempt sees everything configured on the target drive and then can install there.
There could be a flaw in the installation that you have picked up.