gif not lopping

Since some are working and others not, my first suggestion is to check that the GIFs themselves do not have looping limitations that might be at play, particularly if you are using GIFs from sources you had no part in creating. You would need a GIF editor to check this out. e.g in PS, if you open one of the "problem" ones, you can check loop parameters in the Timeline Window, or set it when exporting.

Interactive PDFs can be very fussy in both construction/layout. But I suspect the problem here is that you're using something other than the desktop version of Acrobat to view the PDF. PDF is a universal format but readers vary enormously, and most third-party and nearly all mobile and web readers are poor at managing anything but simple document layouts. Interactive features in particular are only like to work on Acrobat, and the full desktop version (as opposed to any mobile or tablet version) at that.