Disappearing sub-folders in import box

Out of the blue, all my sub-folders disappeared under ONLY "my pictures" folder. All other folders expand to show sub-folders, just not in "my pictures"...and only on import. I've never seen this before. Any advice? Under "my pictures", I should have sub-folders named 2018, 2019, & 2020. And they still exist everywhere else on my computer. I've tried restarting LR.

TIA