Troubleshooting Connecting paperwhite 10th gen to Android 11 hotspot

[helloyou]

Hello all! Apologies in advance if this has already been discussed, but I've tried a few forum searches and wasn't able to find anything exactly on this issue.

I have been trying to get a non-jailbroken paperwhite 10th generation online through a hotspot created by a kinda-dumb phone: a Sonim XP3 running Android 11. If I make an empty file with "WIFI_NO_NET_PROBE" in the USB storage root (a trick I learned on these forums), it will successfully connect to the hotspot, but then will fail to connect to any internet service, as if the hotspot itself was not connected to the internet. But the hotspot works with other devices, including a Windows laptop and another, newer Android phone.

Specifically: initially, all connections to the wi-fi hotspot failed. I also tested this with two other kindles (one a 11th gen paperwhite and another older kindle that I don't have on hand right now), and they both failed, regardless of WPA setting (only WPA2-Personal and no security are available on this hotspot). All three kindles successfully connected to a hotspot created on an Android 12 phone and through an ordinary wi-fi router. After creating the "WIFI_NO_NET_PROBE" file on the 10th gen paperwhite and restarting it, it connected to the hotspot normally. But while connected to the hotspot, no internet-required apps seem to be working properly. The storefront (that you get by tapping the cart icon) will load, but tapping on the links on the page either does nothing or, sometimes, brings up a blank page. When highlighting in a book, the "Translate" and "Wikipedia" context-menu options no longer appear, while the "Share" -> "Goodreads" option will open up Goodreads page, but that fails with the error "The connection has timed out" or "There was a problem connecting to Goodreads". The internet browser also loads a blank page. If I instead connect to wifi through a hotspot created by a phone running Android 12, the internet-required stuff all functions normally--even when I limit the Android 12 phone to 4G/LTE speeds.

This is all consistent with a nonfunctioning or very slow connection between the hotspot and the internet. And that would make sense, since the hotspot is from a low-functionality phone. But the hotspot is working just fine for other devices--only kindles seem to have the problem. So there seems to be something about the interaction between the Android 11 hotspot and the kindle, and as far as I can tell it's not about establishing the WAN connection, but actually getting data from the internet.

Any help or ideas would be greatly appreciated! I'm also happy to provide more information, though I don't actually know how to run diagnostics on the hotspot connection.