Xaiomi door and motion sensors wont stay connected

I bought a few of THESE motion sensors

Got them paired and working with ZHA but, they keep going unavailable. They wont stay connected more than a few hours. They are less than 20 feet from my hub (I’ve got devices much further).

I also have a few of THESE Door/Window sensors. They also will not stay connected. When they work, they also stay on for about a minute when triggered

Any ideas I might try? Do I need to buy the Xaiomi hub (which defeats the purpose of buying these low priced devices)?

You might have an interference problem with WiFi. I would give this article a read and see if this might solve you problem:

https://www.metageek.com/training/resources/zigbee-wifi-coexistence.html