Download galleries are no longer responsive

Recently I noticed my download galleries are no longer responsive. The thumbnail boxes just get smaller and run together. Previously the boxes would switch to a single file vertical column but they no longer do this. If I view them on my desktop iMac they look fine until I reduce the window size to simulate an iPad or my iPhone and then they get funky like I stated above. If I view them on my iPhone they don’t work, either, they appear like the simulation on my iMac. It doesn’t matter what browser I use, either.