Turns out that the issue I was having had nothing to do with the 2.2.18 FW update. My HD simply decided to start failing just around the same time. After I replaced it with a new Seagate 2TB Expansion drive and copied all my recordings over, everything is fine on my end. All my recordings show up again and can be played back without any issue anymore.
One thing I would suggest for Tablo though is to improve error messages and provide access to logs so people can do more informed troubleshooting themselves. I just made a lucky guess by replacing the drive with no indication from Tablo that my drive was on the fritz. The only error message I got once in a while was "Weak Signal" which was more than misleading.
Anyway, I'm happy again and want to state here that my issue was not related to 2.2.18 at all.