Images not uploading to gallery

Hi, I'm new to Squarespace and am wondering why my images are failing to upload. Sometimes I need to try 4-5 times before the image actually uploads. For reference, the images are png thumbnails around 25 kb each. When I save and leave the page, return, or refresh, the places where the images should be appear as gaps on my page. Any reason why this happens? Do I keep attempting to upload over and over again until it succeeds? Thank you. Further note, I have blurred the content not relevant to this post as my website has not yet launched. Cheers.

The number one reason images fail to upload is while they are going up if you chose  any other  tab, like design it will make the upload quit with an error notice sometimes,  but usually no notice. It just isn't there. So when uploading don't choose any other options. Slow internet speed causes failure to upload. We have a lot of that going on right now. Upload one at a time, don't drag too many into the box, makes things too slow, one may load the others fail. 

Thank you Derrick,  I will try that out.