Update...
I upgraded pfSense and Suricata to:
pfSense 2.5.0-RELEASE (amd64)
FreeBSD 12.2-STABLE
Suricata 6.0.0_9
Interestingly, I'm still receiving the entries in the system logs as my initial post, however, not to the degree that I was receiving them when I first posted the issue.
I find that this is only occurring on my wireless LAN segment where a lot of streaming is occurring; Hulu, YouTube, etc.
I had hoped that the pfSense and Suricata updates would have resolved the issue. Hmmm.