I'm running OpenSUSE Leap 15 (actually Leap 15.1).
I only found a download package for Cadabra2-2.2.6.
Are you able to do a build for Leap 15.1?
I have built a package of 2.3.1 for Leap 15.0, now available from the download page; can you give that a shot and let me know?
Cadabra 2.3.1 seems to run ok for me on Leap 15.1.
I'm still re-checking previously reported bugs/problems.