I suspect this an issue with the configuration of the server rather than tor. Where should I start?
tldr: wild guess torrc change (ORPort 443 -> 43) caused this, if 443 is actually intended try changing it.
Is SELinux in enforcing mode?
(see 'sestatus' output)
if yes, try:
tail -f /var/log/audit/audit.log|grep AVC
while starting tor, if you see tor related AVCs you know the reason.
Also make sure this SELinux boolean is on:
getsebool -a|grep tor_can_network_relay
try using port 443 (instead of using 43)
or any of these ports (allowed by SELinux): 80, 81, 443, 488, 6969, 8008, 8009, 8443, 9000, 9001, 9030, 9050, 9051, 9150
if SELinux is not in enforcing mode:
Is anything else binding on that port?