The place edit field acts as both an entry and a search. If you put in a name of a place, and press enter, it will try and find the nearest matching place and put the pin location there. If you don’t press enter after changing that field and then save the observation, it records the place name WITHOUT moving the pin location.
It can be a useful feature… Often I don’t like how the maps label the name for the place, so I can edit it afterward to be more reflective of the place observed. For instance, at our local Eastwoodhill Arboretum the GPS location gets given a name like “Ngatapa 4072, New Zealand” or “Gisborne, NZ-GI-GB, NZ” depending on where in the arboretum the gps location is. That to me is meaningless, so I often change the name to “Eastwoodhill Arboretum, Gisborne, NZ” which makes more sense, or even to “Pear Park, Eastwoodhill, Gisborne, NZ” to bring in the actual area within the arboretum. When I do so, I am careful not to press enter, or it will attempt to find a place called that and move the pin location to there… which often produces strange results! If i accidentally do that, I just exit the observation without saving, and re-edit to try again.