Good news @jess! I figured out what my issue was.
I noticed on the error log in the server that the upstream field was saying: upstream: “https://server_ip:80/hls/p/100/sp/10000/serveFlavor/entryId/0_ss5ctjeb/v/2/flavorId/0_3lpnwekh/name/a.mp4?pathOnly=1”
And figured that the port 80 was probably incorrect. I ran just the nginx config (kaltura-nginx-config.sh) that you mentioned in one of your other posts. The first thing it prompts you for is “Kaltura API host and port (without the protocol)” and mine was defaulting to fqdn:80. When I changed it to fqdn:443, now the videos play as they should. I used an old answers file when I did the upgrade, so I suspect I didn’t setup nginx correctly a couple of years ago (when nginx wasn’t needed).
So my updates go smoothly in the future, do you happen to know which line in the answers file references “Kaltura API host and port (without the protocol)”? Or does this get stored in a config file somewhere outside of the answers file?