The URL example in this bug is formatted incorrectly for search. If searching is the purpose of the URL, it must use referenceContext=search.
https://fieldmaps.arcgis.app/?referenceContext=open&portalURL=https:/supt0014294.esri.com/portal&itemID=845cbd7ea68641a1ac9ed662c198fcd0&search=05210/
If the user wants to use multiple ReferenceContext values in a single URL, such as open and search, only specify one value; the primary use of the ReferenceContext parameter. For example, specifying search implies that the map is open. See the search examples in the doc: https://doc.arcgis.com/en/field-maps/android/help/deploy-your-map.htm#ESRI_SECTION1_F7DE2402BA8743E5BFC4A1241072960E.
The example must look like this: https://fieldmaps.arcgis.app/?referenceContext=search&portalURL=https:/supt0014294.esri.com/portal&itemID=845cbd7ea68641a1ac9ed662c198fcd0&search=05210.