Shield with Oracle - get date format error

I'm trying to test Shield with an oracle database. I was able to install it. I'm able to bring up the login and register views. When I submit the form to register a user I get:
"CodeIgniter\Database\Exceptions\DatabaseException: oci_execute(): ORA-01861: literal does not match format string"
This seems to be caused by the attempt to insert dates for 'created_at' and 'inserted_at' etc. I tried monkeying with the date string that's returned in \vendor\codeigniter4\framework\system\BaseModel.php. If I have it return null for the date then an insertion is made in the 'users' table, but the 'format string' error is still thrown. When I try to log in using the credentials I submitted I get the same 'format string' error, and get the 'Whoops' view. 
This is the version of Oracle I'm using:

"Oracle Database 19c Standard Edition 2 Release 19.0.0.0.0 - Production
Version 19.21.0.0.0"

Any help would be greatly appreciated!! I was asked to evaluate whether or not Shield is an opion for the government agency I'm consulting for and I've had to tell them that it just doesn't work but that I'll see if I can get some support and will get back to them.

Thanks in advance!!
-Jeremy