I have the same issue (or at least a similar-seeming issue) with Firefox. At first I thought it was an issue with my phone’s location system, but it is also an issue with some DSLR images for which I input the locations manually. The pin is in the correct location on the map for the individual observation but is wrong on the Your Observations page.
Some are off by a couple of hundred metres and a couple are off by several kilometres.
EDITED TO ADD: I only posted this because I thought it might help clarify the problem articulated by the OP in the topic from which this has been split. I’ve always thought that the wandering pins were just a manifestation of weirdness that can occur at the intersection of browser optimization, GIS constraints, satellite image resolution and karma.