Orbi RBK352: (DNS?) Issues after restart

A few days ago I got my Orbi. I have set it up in AP mode. The Orbi is directly connected using an ethernet cable to my primary modem/router. Everything works well and the internet/connectivity is great, but somehow after restarting the Orbi I run into very odd internet issues:

• Certain websites will load (e.g. google) but others do not (e.g. github).
• While google works in the browser, pinging google does not (typing `ping www.google.com` in the terminal leads to a time-out)
• I am not able to connect to `orbilogin.com` on my laptop, only on my phone. My phone does have the same issues loading various web pages though.
• The pages that can be loaded and cannot be loaded are consistent (e.g. google is always available, github is never available).
• When this happens, if I connect to the wifi on my main router none of these issues are there and the internet works as expected.

What fixes the problem is switching the Orbi from AP Mode back to Router Mode, and then switching it back to AP Mode. This fixes all of the issues, at least until the next restart, and the internet works great again.

Does anyone have any idea what could cause these issues and how I could resolve them permanently without having to do this switch every time the Orbi is restarted?

The Orbi is on the latest firmware version (V4.4.0.10_2.10.63).

My laptop is a Macbook, and my phone is an iPhone. I tested different browsers (safari, chrome) and the issues were present in every browser. I also tried resetting caches of the browser and that did not fix the problem either.