Photos have mysteriously disappeared from my website

Hello. As the title suggests, somehow the photos have disappeared from my site and I’m not able to recover them. The photos were displayed with no problem for several weeks. I have tried some troubleshooting techniques, including clearing out my browser, clearing my caches, deactivating my plugins, trying out several themes, and restarting my computer. Nothing has worked. The photos do not even display in the twenty sixteen theme. Recently, I have been playing around with different themes, so this might have something to do with it. I also installed a mobile plugin (which I have since uninstalled). This seemed to happened right after I installed this plugin, but I could be mistaken. This seems to have gone beyond my skill set. Any kind of help would be greatly appreciated. My site is https://www.twinleeks.com if you want to give a look. Thanks!