I appreciate all of your help. I guess the best thing to do is jump back to the 2.4G band. Whats weird though, is I found best throughput and range on 5G in my home as opposed to 2.4G. Nonetheless, I'd rather have stability at this point.
The 5 GHz band is split in two: low numbered channels (around 36) and high-numbered (around 150). I've seen some devices work better with high-numbered, and others with low-numbered.
Try with a fixed channel at both end of the channel numbers, see if you get better results with either of them.
Having better throughput on the 5 GHz band makes sense if you have a lot of interference on the 2.4 GHz band (interference from other devices will manifest itself in having a high number of packets being retransmitted, which leads to the drop in performance).