Welcome to the Forums. Sorry to hear about the upgrade issues but as
@m0nkey_ had stated, this can happen with major upgrades. My advice is to dive into the forums and read all of the postings before doing any upgrade and unless you like to troubleshoot problems, do not be an early adopter of the latest software as there is always some bug in it that may or may not affect you. For example I only just upgraded to 11.1-U2 on my backup machine. My main machine will be upgraded after about a month or so when I trust 11.1-U2. I might even just wait until 11.2-U1 comes out. I'm in no hurry. Of course I will spin up a VM to test the new versions but this doesn't always tell me if I'll have issues with my current hard drive pools.
Also, be aware that when 11.2 comes out, iocage replaces warden in the jails. If you upgrade then the jails will need to be upgraded as well. I heard that this should be automatic but I'm certain there will be exceptions so hold on to your knickers.
All I'm saying is to do your best to know what you are getting into before you make any changes to your system.