It looks to me that "use windows file explorer sort order" has stopped functioning altogether!! I tried IG 8.2.6.6 and Win10.1809 and IG always ignored the Explorer sort order.
For example, I had explorer set to "Date Modified" and ImageGlass to "Name", and the sequence IG used was by name. This meant I was skipping some files - at least as far as the Explorer order implied.
If ImageGlass can't / doesn't use the Explorer order, then it goes by the sorting selection in the settings dialog. IG's choices don't include "Date taken", but "Creation Time" should be equivalent to the Explorer "Date Created" column. And I see no obvious difference between Explorer and ImageGlass if I use Name, "Creation Time" or "Length".
If you're skipping images when relying only on (e.g.) Name or "Creation Time" as compared to the Explorer order, then we'll probably need more details - like a set of filenames and creation times. I can't see any problem with my testing files (using the same settings and double-clicking on an image someplace in the middle).
Oh yes, are you using a network or removable drive, or one of your computer local drives?