Thank you for sharing this issue with us.
I see you're using Android. Which version of Field Maps do you have installed?
I understand that this issue happens at random times, but is there a consistent action that can reproduce it? i.e. when it happens, does it only happen when identifying a feature in the map, or can it happen simply panning/zooming around the map?
I understand that you're working in ArcGIS Online, however are the all the services in the map you're using hosted in ArcGIS Online? As oppose to ArcGIS Server?
When did you notice this issue start happening?
@JosephCarl2 Here is the solution:
If you want the background to this here's an article describing what is happening: https://techcrunch.com/2021/09/21/lets-encrypt-root-expiry/
For an Android phone’s built-in browser, the list of trusted root certificates comes from the operating system — which is out of date on these older phones,” Let’s Encrypt explains. “However, Firefox is currently unique among browsers — it ships with its own list of trusted root certificates. This was a clue for us. Note the Sept 30th expiration.
Current workaround (your experience will vary a bit depending on your android version(s) and what browser you use on your desktop; Firefox used here did not try with other browsers):
Manually install R3 cert to device
Click More Information
This fixed Collector and Field Maps but so far not the 3rd party Esri app. I expect this may have far reaching impacts for Esri Partner devs.