Lightroom Classic importing photos into incorrect dated folders

Also, even if the camera clock is set accurately for your home location, travel timezone can have an unwanted effect if you haven't made the right allowance for that within the camera settings. The net effect can be, that all photos actually taken (say) after the local 4pm might file with the subsequent day's photos, or else those taken (say) before the local 11am might file with the previous day's photos, when it comes to importing into LR.

After import to LR the photos can have their capture date and time offset by the right number of hours, regardless whether that is necessary because of a wrong clock or because of timezone - but that's too late so far as auto-filing by date. It's not too big a task to drag the affected photos into the right day folder after this has happened, but it is IMO also worthwhile for the capture time metadata to properly reflect the local time of day when taken.

First thing I would do is to check to see if the camera clock is set properly. If the clock is off by 12 hours (or even some other number of hours), I can see how photos might wind up in different folders.