Cannot install Catalina on external SSD
I'm trying to install Catalina to an external SSD, which worked before but not now. Installation files are put on the target disk, and Mac reboots, but to the login screen of the internal HD, and installation does not proceed.
How can I get the install to proceed?
SSD is formatted as HFS+. Mac is a 2014 iMac (model identifier14,4), with 10.11.6 on internal HD.
It has run on Catalina from the SSD, but there were glitches, and I decided to reinstall from scratch.
iMac Line (2012 and Later)