@scottuf
I spent a whole lot of time experimenting with various dual wan routers. Synology RT2600ac, Cisco RV325, a now obsolete Cisco RV042G, a much newer (and more expensive) Cisco that I can't remember the model name, and an Asus that I also can't remember the model name.
To answer your question, all of the above would properly log every WAN failure (if it detected it in the first place - another whole story...) and most would send to syslog server, email the admin, etc. Only the TP-Link is lacking this obvious feature.
My workplace ending up going with the expensive Cisco units and we continue to use them today. If I seem particularly miffed about this issue, it is because I was the one that pushed to try the TP-Link at work in the first place, and I ended up looking stupid when the unit didn't support this very basic feature. All of them (about a dozen) went back to the vendor. I'm aware of several other lost sales over this dumb oversight too, but I will stop ranting now...
Personally, I kept my TP-Link and still use it. That is why I still hang around here time to time. Every other unit I tested had various other flaws, mostly due to my weird configuration at home, and in the end the TP-Link was the best fit for my personal use. Aside from the lack of proper logging, it is perfect for me in every other regard, which is why I find it crazy they don't fix this issue. It would take what, 12 lines of code?
Anyway, in case anyone is interested, here is my creative kludge to circumvent the issue:
I have both fiber and cable at my house. I setup several rules via group & policy routing that force the Roku on my main living room TV to ONLY use cable and not fail over if it goes out, and my bedroom TV Roku to only use fiber. That way, if one or the other goes down, I will be "notified" rather quickly by someone in my house that one or the other is out since those TV's are on pretty much always when we are home. Works for me. I can expand on how I did it if anyone else ever wants to try something similar.
Or here is a better idea... Hey, TP-Link, FIX THIS once and for all please!