No, that is not normal. Normal is
Perhaps a pain the backside but try from scratch with removing DKIM (yum manager) first and then installing it gain and rebuilding the mailserver once more and then again adding DKIM (if the pane opens then). Just by the way - any fancy defense deployed, e.g. SELinux and/or mod_security or ...?
I would also remove all/any SPF/DKIM/DMARC entries from the zone records and start building them up again one by one. I had some trouble with the CWP DNS mask messing with the records and thus created the records in a text editor, now looking clean in the CWP DNS mask.