I'm trying to get HDR restarted and getting this message:

The secondary server is in Standard mode
onstat -g dri

INFORMIX-OnLine Version 7.23.UC11 -- On-Line -- Up 2 days 16:50:04 -- 501544 Kbytes

Data Replication:
Type State Paired server Last DR CKPT (id/pg)
standard off 617205 / 8

When i issue this command:
onmode -d secondary prod_tcp

I get the following:
DR: Unable to change server type

I have not found any documentation addressing this problem.

BTW We are running IDS 7.23

what is current state of primary and secondary?

Can you do

onstat -
on both primary and secondary and let me know?

Maybe time to consider an upgrade :-) to 11.70 ...
Take a look there

Adding the fact that you can benefit from the Innovator-C Edition if your infrastructure permits it, it's worth taking a look...

If your infra is more 'heavy stuff' you may consider Growth Edition or Ultimate Edition.

This won't resolve your problem, but will give you ideas for the future...

Best
Eric