You installed RHEL 8, and then added the EPEL repo for RHEL 7. This is not compatible with RHEL 8 and packages from EPEL 7 will not function properly.
You can replace EPEL 7 with EPEL 8 when that becomes available, but it does not currently contain certbot and you still will have to wait for it to be built. It may be a few months before EPEL 8 has most or ...
(you didn't mention which Ubuntu release you're running, my examples are from 18.04 LTS)
update-alternatives only works for packages which use the Debian alternatives system. Those packages invoke the update-alternatives command in their maintainer scripts, and have symlinks that point into the /etc/alternatives directory.
Looking at python3, we see that ...
The results of a python ldap3 search are not only attributes but tuples of the form (dn, attributess, raw_attributes), where:
dn: a string containing the DN (distinguished name) of the entry
attributes : a dictionary of returned attributes and their values. Values are list. Values are in UTF-8 format
raw_attributes: same as ‘attributes’ but not encoded (...
The problem was simple enough: the reverse proxy configuration changes the HTTP request (HTTPS scheme to HTTP) which makes the Okta plugin (https://github.com/fangli/django-saml2-auth) fail with the obscure error. Adding the ASSERTION_URL entry to the SAML2_AUTH dict in you settings.py Django file does the trick.