i see a problem only if you’ve re-ordered the observation “cards”, as is now possible since https://forum.inaturalist.org/t/web-uploader-update-duplicate-and-reorder-observations/11467.
for example, suppose you have four observations:
:A: :B: :C: :D:
if you select :A: (the first item) and then shift+click :C: (the 3rd item), then you should see [A], [B], and [C] selected:
[A] [B] [C] :D:
however, suppose you reorder the observations by moving :C: after :D::
:A: :B: :D: :C:
then if you select :A: (the first item) and then shift+click :D: (the 3rd item visually but the 4th item created), you’ll see everything selected:
[A] [B] [D] [C]
alternatively, suppose you reorder the observations by moving :D: before :A::
:D: :A: :B: :C:
then if you select :D: (the first item visually but the 4th item created) and then shift+click :B: (the third item visually but the second item created), you’ll see [B], [C], and [D] selected:
[D] :A: [B] [C]
… in other words, the shift+click operates based on the order of the observations as they were created, not based on the order of the observations as they are represented on the screen.