I believe there are different version of IOS running on the SUP engines. Make sure, they are same. Though being in RPR mode works, but incase if you primary SUP failed due to some reason, then the standby done has to boot in order to take up.
You need to make sure you have the same hardware on both superivors, for example the same ram. Another fact to keep in mind is to have the ios on both supervisors on the same memory. So for example on the active you have it on bootflash then on the slave you must have it on bootflash as well. You can verify the boot statement with a show bootv
We are pleased to announce availability of Beta software for 16.6.3. 16.6.3 will be the second rebuild on the 16.6 release train targeted towards Catalyst 9500/9400/9300/3850/3650 switching platforms. We are looking for early feedback from custome...