@DickyDeath 

Hi,

This is likely a bug in the Tether app.

I've tested this with my RE450 V4 and noticed no issues. What hardware version is yours?

With an older RE365 V1 I can also see that the Tether app changes from "Working Well" to "No Internet" after a while.

Can you get your RE450 to say "Working Well" after tapping on "Check Again"?

Sorry for slow reply to your question, I'm new to the TP-Link community and wasn't sure how to reply. I tried to update my original post with software and firmware versions but site only lets me post once every 24hours. Anyway, my RE450 is on hardware V3.0 firmware, 1.0.1 Build 20190124 Rel. 56886. When I first login to the RE450 through the Tether app it briefly says "Working Well" then flips to "No Internet Connection." Logging out & back in, or turning off & on make no difference. Thanks for looking.

  @DickyDeath 

Ok. Then the RE450 V3 behaves just like my RE365, which is of the same age.

If I check the status of "Internet" on my RE365 V1 via its web interface, then it always says "Connected". I guess it will be the same for your RE450 V3. So, I suggest you confirm the Internet status via the web interface and just ignore the Tether app.