Thought I would post an update. It has been months since I started this thread, with our friend COVID in town and everyone online, bringing the Internet down makes me very unpopular.
Back on April 10, I rolled back to my old hardware. It was running v2.3.5-RELEASE-p2. From April 10 until today (June 28) it has worked perfectly. Never a glitch.
Today the family went out, so I took the opportunity to try switching hardware again.
I made a fresh backup of my v2.3.5-RELEASE-p2 that was running.
I see there has been a new release of PFSense, so I downloaded v2.4.5-RELEASE-p1 and installed it on my new box.
Restored the backup and everything is running perfectly. No packet loss every 15 minutes.
I looked at the release notes for 2.4.5-p1 and don't see anything that jumps out at me.
Guess I will never know what the true cause of the problem was, but glad to have my new hardward back in place without any packet loss as my old hardware could was limiting my connection speeds.